In my .js file:

PrintClaimsTab()

{

.

  var tableElement = document.getElementById("GridViewClaims");

  for (var i=0;i < tableElement.rows.count; i++)  {

    var rowElem = tableElement.rows[i];

    var tablerow = '<tr>';

    for (var x=0;x < rowElem.cells.count;x++)  {

      var cell = rowElem.cells[x];

      tablerow = tablerow + '<td>' + cells[x].value + '</td>';

    }

    tablerow = tablerow + '</tr>';

    printWindow.document.write(tablerow);

  }

}

But tableElement is always null.

I have also tried:

<input type="button" value="Print" onclick="JavaScript:PrintClaimsTab(<%=GridViewClaims.ClientID%>)" />

And PrintClaimsTab(GridViewID) { var tableElement = document.getElementById(GridViewID); }

In which tableElement is also null.

A different function, which refers to a div, sets tableElement correctly.  Any ideas?

This should work:

    function PrintClaimsTab(elemId) {
        var tableElement = document.getElementById(elemId);

        if(tableElement == null) { alert('Null'); return false; }

        for (var i=0;i < tableElement.rows.count; i++)    {
            var rowElem = tableElement.rows[i];
            var tablerow = '<tr>';
            for (var x=0;x < rowElem.cells.count;x++)    {
                var cell = rowElem.cells[x];
                tablerow = tablerow + '<td>' + cells[x].value + '</td>';
            }
            tablerow = tablerow + '</tr>';
            printWindow.document.write(tablerow);
        }
    }

 Button:

    <input type="button" value="Print" onclick="PrintClaimsTab('<%=GridViewClaims.ClientID%>');" />

Hope this helps!  Don't forget to mark the most helpful post(s) as Answer for the sake of future readers.  Thanks!

That did it.  Thanks very much.