Hi Atteqpasha,

The checkbox can be placed inside the header in the HeaderTemplate section of a template column. Please visit the following link to learn more about this:

http://help.infragistics.com/Help/NetAdvantage/ASPNET/2009.1/CLR3.5/html/WebGrid_Using_Column_Templates.html

Then the OnClick event of the CheckBox control placed in the header can be handled on the client side to select all the check boxes placed in the column.

(<asp:CheckBox ID="chb_IsNew_Header" runat="server" onClick="HeaderCheckedChanged(this )"/>

//JavaScript method:

function HeaderCheckedChanged(sender)

{

var grid = igtbl_getGridById("<%= UltraWebGrid1.ClientID %>");

var column = igtbl_getColumnById(sender.parentElement.id);

//Here you can check all the check boxes in the cell template

}

Here is another link which could be a good starting point. 

Hope this helps.

Thanks

Sarita