In you are using a RowChecker column, you will need to use this RowValidate client side event handler:

function WebGrid1_OnRowValidate(rowObject)
{
	if(rowObject.getAttribute('type') == "NewRow")
	{
	    rowObject.childNodes[1].innerHTML = '<input class="DefChkBox" type="checkbox" rowchecker="1" hidefocus="hideFocus"/>';
	}
	return true;
}

Hi Glenn,

thanks for your reply.

I tryed your snippet, rowchecker is my first column of webgrid, but on add row I got an error (Null reference object, see image attached).

The null reference error seems to be caused by a WebGrid bug. A bug report has been submitted to our developer. We will inform you if there is any update or progress regarding this issue.

I have just been updated regarding this issue, the fix will be available on the next hotfix release.