function sum() {
	var c1 = Math.floor(eval(document.bfm.c1.value));if(!c1){c1 = 0;}
	var c2 = Math.floor(eval(document.bfm.c2.value));if(!c2){c2 = 0;}
	var c3 = Math.floor(eval(document.bfm.c3.value));if(!c3){c3 = 0;}
	var c4 = Math.floor(eval(document.bfm.c4.value));if(!c4){c4 = 0;}
	var p1 = c1*350;
	var p2 = c2*380;
	var p3 = c3*350;
	var p4 = c4*350;
	document.bfm.c1.value = c1;
	document.bfm.c2.value = c2;
	document.bfm.c3.value = c3;
	document.bfm.c4.value = c4;
	document.bfm.p1.value = p1;
	document.bfm.p2.value = p2;
	document.bfm.p3.value = p3;
	document.bfm.p4.value = p4;
	document.bfm.price.value = p1+p2+p3+p4;
	document.bfm.weight.value = (c1+c2+c3+c4)/10;
}