function valueCheck()
{
	var surface = window.document.sizing.area.value.length;
   	var atemp = window.document.sizing.air.value.length;
   	var wtemp = window.document.sizing.water.value.length;	
	if (surface < 1 || atemp < 1 || wtemp < 1) return false;
        calcSize();
}