function prddCalc() {
	var stdtotaltubes = 0;
	var ulttotaltubes = 0;
	var sqfttotal = 0;
	var stdtotalsqft = 0;
	var ulttotalsqft = 0;

	for(i = 1; i <= 6; i++) {
		objWidth = getElement('width' + i);
		objHeight = getElement('height' + i);
		if( objWidth != null && objHeight != null) {
			var sqft = trim(objWidth.value) * trim(objHeight.value);
			setSpanText('sqft' + i, sqft);
			sqfttotal += sqft;

			objCoverage = eval('document.calcform.coverage' + i);
			if(objCoverage != null) {
				if(objCoverage[0].checked) {
					// standard
					stdtotalsqft += sqft;
				} else if(objCoverage[1].checked) {
					// ultra
					ulttotalsqft += sqft;
				}

			}
		}

	}

	setSpanText('sqfttotal', sqfttotal);

	stdtotaltubes = Math.ceil(stdtotalsqft/32 * 2);
	ulttotaltubes = Math.ceil(ulttotalsqft/32 * 3);
	var totaltubes = stdtotaltubes+ulttotaltubes;
	var totalcases = Math.ceil(totaltubes / 12);

	setSpanText('totaltubes', totaltubes);
	setSpanText('totalcases', totalcases);

}

function prddSelectAll(theform, seltype) {

	for(i = 1; i <= 6; i++) {
		objCoverage = eval('document.calcform.coverage' + i);
		if(objCoverage != null) {
			if(seltype == 'S') {
				objCoverage[0].checked = true;
			} else if(seltype == 'U') {
				objCoverage[1].checked = true;
			}
		}
	}
}