Hello, I have a form that has item 1 - item 1's cost is determined by the length and width (square feet) and by the material price. This generates totalcost (for item 1)

Same thing happens for item 2.. This generates totalcost2 (for item2)

Now I need to create a function that will grab the content/values of these totals and display a TOTAL VALUE.. I would think this would be simple but I can't seem to figure it out.

Again totalcost + totalcost2 = grandTotal

Any help would be appreciated - function code and html for webpage.
Thx