function spaceSum(){
	x = parseInt(document.getElementById('FloorSpaceX').value);	
	y = parseInt(document.getElementById('FloorSpaceY').value);	
	if(x > 0 && y > 0){
		sum = x * y;
		document.getElementById('FloorSpaceSum').value = sum;	
	}
	else if(x > 0 || y > 0){
		document.getElementById('FloorSpaceSum').value = 0;	
	}
	else{
		document.getElementById('FloorSpaceSum').value = "";	
	}
	
}