function initHighlight() {
    if (!document.getElementsByTagName){ return; }
    var allfields = document.getElementsByTagName("input");

    for (var i=0; i<allfields.length; i++){
        var field = allfields[i];
        if ((field.getAttribute("id") == "ctl00_Search1_txtSearch") ) {
            field.onfocus = function () {this.className = 'Text Highlight'; if (this.value == 'Enter a model number...') { this.value=''; }}
            field.onblur = function () {this.className = 'Text SearchText'; if (this.value == '') { this.value='Enter a model number...'; }}
        }
    }
}

function addLoadEvent(func) {
    var oldonload = window.onload;
    if (typeof window.onload != 'function'){
        window.onload = func;
    } else {
        window.onload = function(){
        oldonload();
        func();
        }
    }
}

addLoadEvent(initHighlight);