Question

I have a html table like this:

     Invoice#          Due Date      Balance      Select 
      12345           12/25/2011    $1,356.00       X
      56789           12/30/2011    $1,000.00       X

      Total:                        $2,356.00

Below the table I have a textbox. When the checkbox in a row is selected or deselected, I want the value of the textbox to update to add or subtract the balance in the selected row, i.e. subtract the balance stated in the row when the checkbox is unchecked, and add it when checked. By default the boxes will be checked.

Answer 1

Assuming jQuery:

$('table input[type="checkbox"]').click(function() {
    var curBalance=new Number($("#textbox").val());
    var rowBalance=new Number($(this).parent().prev().text());

    var newNum=0;
    if (this.checked) newBalance=curBalance+rowBalance;
    else newBalance=curBalance-rowBalance;

    $("#textbox").val(newBalance);
});