The method by which the js script gets the webform server control

Net webform to get the server control,js script to get the server control needs to use ClientID

Web foreground acquisition control:
< % % = TextBox1. The ClientID > The control ID for TextBox1 is printed
Get the webform control in the js script :(implements the control to become red when the mouse moves over it)

 
<script type="text/javascript"> 
function myFuntion() 
{ 
document.getElementById('<%=TextBox1.ClientID %>').onmouseover=function(){ 
this.style.background='red'; 
} 
} 
</script>