set val of input box on click in table cell

set val of input box on click in table cell

I have a table with one click-able cell (ancor tag).  Here is the code for the cell:  (php)

echo("<td class=\"tdclick\"><a href=\"javascript:;\" onClick=\" = \"settrnum($fnum));\">$fnum</a>");

Here is what I tried: 
        $(function settrnum(fnnum){
            $('tdclick').onclick = {
               $("#flightno").innerHTML = this.val;
            };
        });


#flightno is the id of the input field I need to set the value = to table cell value.


 It doesn't work.   Any help is appreciated.