For Sorting I have used two dropdowns:

For displaying the Fields on which sorting is to be done

For displaying the sort order - Ascending or Descending

The dropdown, which shows the Field, picks up the values from the Header Table tblHeader.

The Header Text could be anything, but make sure you place it in correct order since it uses the index of the Column to identify the Column Name in the DataTable. For example, if the CustomerID is the first Column, that is index value 0 in the DataTable. So it should be first here so that the index value is picked up correctly.

Listing 16

function PopulateDropDown()
{
    var tblHeader = document.getElementById("tblHeader"); 
    var ddlSort = document.getElementById("ddlSort"); 
    var tblCells = tblHeader.getElementsByTagName("TD");
    for (var i=0; i<tblCells.length;i++)
    {
        var opt = document.createElement("option");
        ddlSort.options.add(opt);
        opt.text = tblCells[i].innerHTML;
        opt.value = i;
    }
}