display sort arrow on table render, not just after column header is clicked

[jwesneski]

i'm using the MIT freelicense 'sorttable.js' javascript to make an html table sortable by clicking on the column headers. i'm not very good at javascript (yet) and would like the script to display the arrow the first time the table renders, not wait until a column header has been clicked. i'd like to display the down arrow upon initial page load/table render. i've tried monkeying around with it, to no avail. it's a little beyone me at this stage, i'd appreciate any guidance.
(you can find 'sorttable.js' under google.)

[manmadareddy]

Just call the same function which is executing upon clicking the fields
when the body load also.