how to show a textbox(visible=true) based on dropdownlist selection using client scri

[arun_mrk]

Initially when the page is load i had set a textbox property to visible false

txtGrpName.Visible=false;

If user change the default item in a dropdownlist(ddlGrpName) then i have to show the textbox

so i have written client side script

<script language="javascript">
function CheckGroup()
{
  if (Register.ddlGrpName.value==-1)
  {
    Register.txtGrpName.style.visibility=visible;
  } 
  else
  {
				
    Register.txtGrpName.style.visibility=hidden;
  }
}
</script>

and in code behind
i have added

ddlGrpName.Attributes.Add("onchange","CheckGroup();");

but his code doesnt work because txtGrpName is not visible at the time of display so i couldnt again
reset to visible =true in client script.

How to do it done?


[edit]Please use

 tags [/ cs] or [code=vb] tags [/ vb] , <code> tags </code> do not work[/edit][/COLOR]