This is an emulation of the Windows.Forms ComboBox. It is the combination of a 
Textbox, with a DropDownList. For browsers with good script and css support, the 
control will display as a normal ComboBox. For older browsers or those with poor 
script or css support, the control will display as a pair of controls, one 
TextBox and one DropDownList. Either way the serverside progmattic interface 
will be the same.

        <span id="_ctl0_PageContent_MyList_Container"><input name="_ctl0:PageContent:MyList:Text" type="text" id="_ctl0_PageContent_MyList_Text" autocomplete="off" /><span id="_ctl0_PageContent_MyList_Button"></span></span><select name="_ctl0:PageContent:MyList" onchange="ComboBox_SimpleAttach(this, this.form['_ctl0:PageContent:MyList:Text']); " listSize="4" id="_ctl0_PageContent_MyList">
	<option value="Colorado">Colorado</option>

	<option value="New York">New York</option>
	<option value="New Hampshire">New Hampshire</option>
	<option value="Texas">Texas</option>
	<option value="California">California</option>
	<option value="Florida">Florida</option>
	<option value="United States Of America">United States Of America</option>

</select>
<script language="javascript">
<!--
	var ComboBoxes =  new Array('_ctl0_PageContent_MyList');
	var DefaultButtons =  new Array("_ctl0_Email©__doPostBack('_ctl0:NotificationsSubscribe','')©False");
		// -->
</script>

			
<script language="javascript">
<!--
if ( typeof( window.addEventListener ) != "undefined" ) {
	window.addEventListener("load", ComboBox_Init, false);
} else if ( typeof( window.attachEvent ) != "undefined" ) {
	window.attachEvent("onload", ComboBox_Init);
} else {
	ComboBox_Init();
}
//-->
</script>	

Spin Control Example:

<script>
<!--
function UpDown_Increment(textBoxId,increment) {
	var textBoxControl = UpDown_GetTextbox( textBoxId );
	if( textBoxControl != null ) textBoxControl.value = parseInt(textBoxControl.value) + increment;
}
function UpDown_Decrement(textBoxId,increment) {
	var textBoxControl = UpDown_GetTextbox( textBoxId );
	if( textBoxControl != null ) textBoxControl.value = parseInt(textBoxControl.value) - increment;
}
function UpDown_GetTextbox(textBoxId) {
	for( var i=0; i<document.forms.length; i++ ) {
		var theForm = document.forms[i];
		if( typeof(theForm[textBoxId]) != "undefined" ) {
			var textBoxControl = theForm[textBoxId];
			if ( isNaN( parseInt( textBoxControl.value ) ) ) textBoxControl.value = 0;
			return textBoxControl;
		}
	}
	return null;
}
//-->
</script>