Application Express :: How To Calculate Total Column Dynamically In Tabular Form

I am trying to calculating the total column based on two columns, Total=unitprice*no.of items

I wrote this Javascript in page properties>javascrpt>Execute when Page Loads

"$('input[name=f05],input[name=f06]').change( function(){
parent_row = $(this).parents('tr:first');
sal = ( parent_row.find('input[name=f05]').val() == ' ') ? 0 : parseFloat(parent_row.find('input[name=f05]').val() );
comm = ( parent_row.find('input[name=f06]').val() == ' ') ? 0 : parseFloat(parent_row.find('input[name=f06]').val() );
total = sal * comm;
parent_row.find('input[name=f07]').val(total);
});

But its not Giving any result in total column?