| function calculate(fld,
price) { // fld will equal pw1 or pe1 var dir = fld.name.charAt(1); // used to determine whether it is the East or West Form var num = fld.name.charAt(2); // what Item number is it var quant = fld.options[fld.selectedIndex].value; // how many of the items did the User choose var subtotal = eval(quant * price); // the eval converts a string to an Object property - in this case the value // dir = East or West & num = Item number // with this information we can post the result to appropriate Form & // to the appropriate Field on the Form eval('document.order.t' + dir + num).value = fix(subtotal); var total = 0; // this loop sums the totals for each of the Items to give us the Grand Total for that Form for (i = 1; i < 8; i++) { // does that particular Item have a "total" - in other words did the User choose this Item var itemTotal = eval('document.order.t' + dir + i).value; // total is a running sum of the Form's "subtotals" if (parseFloat(itemTotal) > 0) total += parseFloat(itemTotal); } // prior to sticking in the Grand Total into the Total Field we need to "dollarize" the number eval('document.order.total' + dir ).value = fix(total); } // a number like 6.6 should ultimately read as $6.60 and not $6.6// a number like 6.6275 should ultimately read as $6.63 // the fix(total) function takes care of these particular problems function fix(total) { // ie, total == 6.6275 var dollars = Math.floor(total); // dollars = 6 // browsers sometimes have rounding errors - 662.75 - 600 = 62.75 var cents = (total * 100) - (dollars * 100); cents = Math.round(cents); // 63 if (cents < 10) cents = "0" + cents; // .998 will become 1.00 so we need to increment the dollar value by one if (cents == 100) dollars++; // if cents equal 0 then dollars equal total or total + 1 incase of .998 if (dollars == total || dollars == Math.floor(total) + 1) cents = "00"; total = dollars + "." + cents; // 6.63 return total; } |