ASP.NET TextBox MultiLine plus MaxLength

Solution:

javascript:
function checkTextAreaMaxLength(textBox,e, length)
{

var mLen = textBox["MaxLength"];
if(null==mLen)
mLen=length;

var maxLength = parseInt(mLen);
if(!checkSpecialKeys(e))
{
if(textBox.value.length > maxLength-1)
{
if(window.event)//IE
e.returnValue = false;
else//Firefox
e.preventDefault();
}
}
}
function checkSpecialKeys(e)
{
if(e.keyCode !=8 && e.keyCode!=46 && e.keyCode!=37 && e.keyCode!=38 && e.keyCode!=39 && e.keyCode!=40)
return false;
else
return true;
}


How to used:

asp:TextBox Rows="5" Columns="80" ID="txtCommentsForSearch" MaxLength='1300' onkeyDown="checkTextAreaMaxLength(this,event,'1300');" TextMode="multiLine" runat="server"