[VS2005] Textbox Auto Expand

Here is an example of auto expand a textbox.

1. Control declaration:

<asp:TextBox ID=”txtMsg” runat=”server”  TextMode=”MultiLine” style=”overflow:hidden” onkeyup=”AutoExpand(this, event)” Rows=”2″ />

2. JavaScript function:

function AutoExpand(txtBox, event)
{
if (event.keyCode == “13” || event.keyCode == “8”) {
var therows = 0
var thetext = document.getElementById(txtBox.id).value;
var newtext = thetext.split(“\n”);
therows += newtext.length

document.getElementById(txtBox.id).rows = therows;
return false;
}
}