The issue is documented in this JSFiddle:
http://jsfiddle.net/sawaira/j62309fx/39/
 <div style="height:700px; width:1500px;">
        <div id="loading-image">Stabilizing iteration (90% done)</div>
        <div id="kl" style="position:absolute;height:700px; width:1200px;float:left;border: 2px solid 
#0094ff;overflow:auto">
        </div>
        <div style="height:100%; width:300px;float:right;border: 2px solid #0094ff;border-radius:5px">
            <div style="height:100%; width:100%;">
                <table style="width:100%;">
                    <tr>
                        <td colspan="4">
                            <div class="containerChart2">
                                <div class="headerChartControl">
                                    <span>My Team(s):</span>
                                </div>
                                <div id="filterHolder1" class="listControl">
                                     <form id="formUserListObject">
                                         <input type="checkbox" name="userSelection" id="{{id}}" 
onchange="checkBoxSelected(id,false)" class="css-checkbox"/>
        <label for="{{id}}" class="css-label">
            {{userName}}
        </label>
    </form>
                                </div>
                            </div>
                        </td>
                    </tr>
                          <tr>
                        <td colspan="4">
                            <div class="containerChart2">
                                <div class="headerChartControl">
                                    <span>Find Other Team(s):</span>
                                </div>
                                <div class="contentSearch">
                                    <!-- This is the HTML element that will be used to render the KeyLines 
component -->
                                    <form id="formSearch" class="formSearch">
                                        <input type="search" id="searchBox" />
                                    </form>
                                    <!--label id="headervalue2">Search Results:</label-->
                                    <div id="filterHolder2" class="listControl"></div>
                                </div>
                            </div>
                        </td>
                    </tr>
                        <td colspan="4">
                                   <div class="headerChartControl">
                                           <input type="button" onclick="document.getElementById('loading-
image').style.display ='block'" value="Show"/>
    <input type="button" onclick="document.getElementById('loading-image').style.display ='none'" value="Hide"/>
                                </div>
                            </td>
                        </tr>
                    </table>
                </div>
     </div>
    </div>
    #formUserListObject {
            font-size: x-small;
        }
        #tab0 {
            top: 50px;
        }
        #page {
            display: none;
        }
        #loading-image {
            position:absolute;
            top: 50%;     
            left:50%;            
            z-index:1;
            font-size: 20px;
            color: red;
        }
        .overallDiv {
            height: 100%;
            width: 100%;
            background-color: #ff6a00;
        }
        .myDiv {
            height: 100%;
            width: 100%;
            background-color: #b6ff00;
        }
        .formClass {
        }
        .listControl {
            padding-top: 5px;
            padding-right: 15px;
            padding-bottom: 5px;
            padding-left: 15px;
            border: 2px solid #0094ff;
            height: 100px;
            overflow-y: scroll;
        }
        .paddingControl {
            padding-top: 5px;
            padding-right: 10px;
            padding-bottom: 5px;
            padding-left: 10px;
        }
        .slider {
            padding-top: 5px;
            padding-right: 15px;
            padding-bottom: 5px;
            padding-left: 15px;
            background-color: #00ff90;
        }
        input[type=checkbox].css-checkbox {
            position:absolute;
            z-index: -1000;
            left: -1000px;
            overflow: hidden;
            clip: rect(0 0 0 0);
            height: 1px;
            width: 1px;
            padding: 0;
            margin: -1px;
            border: 0;
        }
        input[type=checkbox].css-checkbox + label.css-label {
            padding-left: 20px;
            height: 15px;
            display: inline-block;
            line-height: 15px;
            background-repeat: no-repeat;
            background-position: 0 0;
            font-family: Arial;
            font-size: 10px;
            cursor: pointer;
        }
        input[type=checkbox].css-checkbox:checked + label.css-label {
            background-position: 0 -15px;
        }
        label.css-label {
            background-image: url
(http://csscheckbox.com/checkboxes/u/csscheckbox_845137eccd6f9ac2355055adf283a248.png);
            -webkit-touch-callout: none;
            -webkit-user-select: none;
            -khtml-user-select: none;
            -moz-user-select: none;
            -ms-user-select: none;
            user-select: none;
        }
        input[type=checkbox].css-checkbox + label.css-labelMinus {
            padding-left: 20px;
            height: 15px;
            display: inline-block;
            line-height: 15px;
            background-repeat: no-repeat;
            background-position: 0 -15px;
            font-family: Arial;
            font-size: 10px;
            cursor: pointer;
        }
        input[type=checkbox].css-checkbox:checked + label.css-labelMinus {
            background-position: 0 -15px;
        }
        label.css-labelMinus {
            background-image: url
(http://csscheckbox.com/checkboxes/u/csscheckbox_845137eccd6f9ac2355055adf283a248.png);
            -webkit-touch-callout: none;
            -webkit-user-select: none;
            -khtml-user-select: none;
            -moz-user-select: none;
            -ms-user-select: none;
            user-select: none;
        }
        .headerChartControl {
            background-color: #9ed1f6;
            cursor: pointer;
            font-family: Arial;
            font-size: 12px;
            font-weight: bold;
            width: 100%;
        }
        .contentSearch {
            width: 100%;
        }
        .listControl {
            border: 1px solid #0094ff;
            height: 100px;
            overflow-y: scroll;
        }
        .searchText {
            font-family: Arial;
            font-size: 10px;
        }
        .formSearch {
            width: 100%;
            display: inline-block;
            padding-bottom: 2px;
        }
        input[type="search"] {
            background: white url
(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAwAAAAMCAMAAABhq6zVAAAAIVBMVEW/v7+/v78AAAC/v7+/v7+/v7+/v7+/v7+/v
7+/v7+/v79QUkolAAAAC3RSTlOLYAAJeoMjRhpOcbsbtd4AAABJSURBVHjaVc1JDsAgDATB9uAF8v8Hx0QcSN9KssZI5eClDj18PRsFlmlQDcfUG
d6A3EgYP1xncQ+sa5qYOk9jRQt1Y0izhU5bL2o2AW3ZQKeJAAAAAElFTkSuQmCC) 10px 6px no-repeat;
            height: 20px;
            border: 1px solid #0094ff;
            width: 100%;
        }
    input[type="search"] {
      -webkit-box-sizing: border-box;
     -moz-box-sizing: border-box;
          box-sizing: border-box;
     -webkit-appearance: textfield;
    }
        input[type="search"]::-webkit-search-cancel-button {
            -webkit-appearance: searchfield-cancel-button;
        }
        input[type="search"]::-webkit-search-decoration {
          -webkit-appearance: searchfield-decoration;
        }
I have added 2 buttons to show and hide the Loading text. I want the "Loading Text" itself to always be positioned in the middle of the "kl" div, even on scroll/resizing of window.
Even with top/left = 50% and position=absolute, the text is not centered (mainly on resizing). What do I need to change to get it centered properly.
                        
Check this
:http://jsfiddle.net/8b6zk90cjust i added position:relative to outer and inner div to position:fixed