<head>
function chk()
{
var x=document.getElementByID("txtmax");
}
</head>
<body>
<form runat="server" id="form1">
MaxValue:<asp:textbox id="txtboxmax" runat="server" />
<asp:gridview id="gr" runat="server" >
<columns>
<asp:templatecolumn>
<asp:textbox id="txtboxmin" runat="server" />
<asp:CustomValidator ID="cv" runat="server" EnableClientScript="true" ControlToValidate="txtmin" ClientValidationFunction="Chk()" ErrorMessage="*" />
</asp:templatecolumn">
<asp:boundfield datafield="name"/>
</column>
</asp:gridview>
</form>
</body>
i want compare the value of txtmax in the GridView with the txtmin through javascript.if txtmax value is greater than txtmin value.then custom error (*) should displayed.above is my code.the problem how can i pass my txtmax value to chk() function.Pls help.