function change_display(id){
		d = document.getElementById(id);
		
		h = document.getElementById('head_' + id);
		if (d.style.display == "block"){
			d.style.display = "none";
			h.style.display = "none";
		} else {
			d.style.display = "block";
			h.style.display = "block";
			
		}
	}
	
	function sum_smeta(){
		 suma = 0;
		 inp = document.smeta.elements;
		 inpLen = document.smeta.elements.length;
		 for (i = 0; i < inpLen; i++){
		 	if (inp[i].type == "text"){
		 		if(parseFloat(inp[i].getAttribute("price").replace(",","."))*parseFloat(inp[i].value))
		 			suma = suma + parseFloat(inp[i].getAttribute("price").replace(",","."))*parseFloat(inp[i].value);

		 	}
		 }
		sm = new Number(suma);
		suma = sm.toFixed(1);
		 document.getElementById("total").innerHTML = suma;
	}
	
	function sum(inp){
			num = inp.getAttribute("price");
			num = num.replace(",", ".");
			num = parseFloat(num)*parseFloat(inp.value);
			num = num.toFixed(1);
			document.getElementById("sum_" + inp.getAttribute("sum_id")).innerHTML = num;
	}
	
	function clearform(){
		document.smeta.reset();
		document.getElementById('total').innerHTML = 0;
	}
	
	function keyCheck(ev)
	{
		k = ev.keyCode;
		if ((k < 48 || k > 57) && k != 8 && k != 37 && k != 39 && k != 190) 
			return  false; 
	}