<script type="text/javascript">
function SelectAll(id)
{
//get reference of GridView control
var grid = document.getElementById("<%= GridView1.ClientID %>");
//variable to contain the cell of the grid
var cell;
if (grid.rows.length > 0)
{
//loop starts from 1. rows[0] points to the header.
for (i=1; i<grid.rows.length; i++)
{
//get the reference of first column
cell = grid.rows[i].cells[0];
//loop according to the number of childNodes in the cell
for (j=0; j<cell.childNodes.length; j++)
{
//if childNode type is textbox or label or...
if (cell.childNodes[j].type =="TextBox")
{
//perform ur task here
}
}
}
}
}
</script>