check box in grid

Question

Hi, I have a checkbox for each row of my web datagrid. Now in the header I have placed a checkbox. The idea is that when the check box in the header is checked then all the checkboxes in the grid get checked (Similar to hotmail style). I have also written the javascript but when I click on the checkbox nothing happens. In fact in the status bar of the IE it says, "Error on page". Any thoughts please? Thanks This script is in the header section of the html ---------------------- This is the grid bit which is supposed to call the function