Check/uncheck GridView Header checkbox using Javascript Code

<script type="text/javascript"> function SelectAll(id) { var grid =  document.getElementById("<%= GridView1.ClientID %>"); variable to contain the cell of the grid var cell; if (grid.rows.length > 0) { for (i=1; i<grid.rows.length; i++) { cell = grid.rows[i].cells[0]; for (j=0; j<cell.childNodes.length; j++) { if (cell.childNodes[j].type =="checkbox") { cell.childNodes[j].checked =  document.getElementById(id).checked; } } } } } </script>   Server side binding for checkbox is as follow:   protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e) { if (e.Row.RowType == DataControlRowType.Header) { ((CheckBox)e.Row.FindControl("cbSelectAll")). Attributes.Add("onclick", "javascript:SelectAll('" + ((CheckBox)e.Row.FindControl("cbSelectAll")).ClientID + "')"); } }