Copy on Clipboard using Javascript

I needed to have functionality of copying contents of textbox on clipboard at my aspx page. This is how I implement it

Objects:

Width="596px">

Script:

function CopyToClipboard()

{

var textboxVal = document.getElementById("txtScript").value; //txtText id of a textbox

if( window.clipboardData && clipboardData.setData )

{

clipboardData.setData("Text", textboxVal);

}

else

{

//alert("You should upgrade you browser,works only in IE4+");

}

}