OK!I can see why and also understand why.
I’m grateful for your answers that have helped me a lot.
I’m now thru this topic and have finally a solution that I enclose below.
Thanks! 
 
ITMA
<script type="text/javascript">
    function on_hoursvars_begin_edit(cell) {
        a_curItemIndex = cell.getItemIndex();
        //Get the current cell value. Unlike the previous
        //sample, this sample displays "Product_Name", but
        //actually stores "Product_No".
        var v = cell.getValue();
        //Set the drop down box's selectedIndex based on the
        //current value. Each drop down item's "value" property
        //contains the "Product_No".
        var dropDownBox = document.getElementById("ddlhoursvars");
        for (var i = 0; i < dropDownBox.options.length; i++) {
            if (dropDownBox.options[i].value == v) {
                dropDownBox.selectedIndex = i;
                return;
            }
        }
        //No match has been found, display the "Please Select" item
        dropDownBox.selectedIndex = 0;
    }
    function on_hoursvars_end_edit(cell) {
        //Get the new value from the drop down box
        var dropDownBox = document.getElementById("ddlhoursvars");
        var selectedIndex = dropDownBox.selectedIndex;
        if (selectedIndex > 0)
            return dropDownBox.options[selectedIndex].value;
        return null;
    }
    function on_hoursvars_column_gettext(column, item, cellValue) {
        //Gets values from a textcolumn that is hidden
        var dropDownBox = document.getElementById("ddlhoursvars");
        return column = item.getCell(9).getValue();
    }
</script>
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