var error;
	var err_0 = "U heeft nog niet alle velden ingevuld!\n\n";
	var err_w1 = "Breedte: Waarde ingeven aub!\n";
	var err_w2 = "Breedte: Ongeldige ingave - alleen gehele getallen ingeven!\n";
	var err_d1 = "Lengte: Waarde ingeven aub!\n";
	var err_d2 = "Lengte: Ongeldige ingave - alleen gehele getallen ingeven!\n";
	var err_h1 = "Hoogte: Waarde ingeven aub!\n";
	var err_h2 = "Hoogte: Ongeldige ingave - alleen gehele getallen ingeven!\n";
	var err_m1 = "Aantal: Waarde ingeven aub!\n";
	var err_m2 = "Aantal: Ongeldige ingave - alleen gehele getallen ingeven!\n";
	var err_mat1 = "Materiaal: U heeft nog geen materiaal geselecteerd!\n";
	
	//var mat = new Array(new Array(24.18,7.2),new Array(24.18,7.2),new Array(49.3,7.2),new Array(51.36,11.4));
	var mat = new Array(new Array(24.18,7.2),new Array(24.18,7.2),new Array(48.4,7.2),new Array(36.2,11.4));
	var cw, cd, ch, cq;
	
	var currMat = 1;
			
	function setMaterial(newMat){
		currMat = newMat;
	}
	
	function is_valid_num(input){ if (isNaN(input) == true) return false; return true; }
	function is_calc_width_valid(input){ if(input == ""){ error += err_w1; return false; } else{ if (is_valid_num(input) == false){ error += err_w2; return false; } } return true; }
	function is_calc_depth_valid(input){ if(input == ""){ error += err_d1; return false; } else{ if (is_valid_num(input) == false){ error += err_d2; return false; } } return true; }
	function is_calc_height_valid(input){ if(input == ""){ error += err_h1; return false; } else{ if (is_valid_num(input) == false){ error += err_h2; return false; } } return true; }
	function is_calc_qty_valid(input){ if(input == ""){ error += err_m1; return false; } else{ if (is_valid_num(input) == false){ error += err_m2; return false; } } return true; }
	function is_calc_material_valid(input){ if((is_valid_num(input) == false) || (input == 0)){ error += err_mat1; return false; } return true; }
	
	function CheckInputs(){
		var check_ok = true;
		error = err_0;
		check_ok = (is_calc_width_valid(document.calculateForm.calculateFormInputWidth.value) && check_ok);
		check_ok = (is_calc_depth_valid(document.calculateForm.calculateFormInputDepth.value) && check_ok);
		check_ok = (is_calc_height_valid(document.calculateForm.calculateFormInputHeight.value) && check_ok);
		check_ok = (is_calc_qty_valid(document.calculateForm.calculateFormInputQuantity.value) && check_ok);
		check_ok = (is_calc_material_valid(currMat) && check_ok);
		if(check_ok == false){alert(error);}
		return check_ok;
	}
	
	function calcArea(){
		var v1 = cw*ch*2;
		var v2 = cd*ch*2;
		var v3 = cw*cd*2;
		var face = ((Math.round(((v1+v2+v3)/1000000)*100))/100)*cq;
		var fTxt = face.toString(10);
		return fTxt.replace(/\./,",");
	}
	
	function calcWeight(){
		var v1 = cw*ch*2;
		var v2 = cd*ch*2;
		var v3 = cw*cd*2;
		var flaeche = ((Math.round(((v1+v2+v3)/1000000)*100*mat[currMat][1]))/100)*cq;
		var flTxt = flaeche.toString(10);
		return flTxt.replace(/\./,",");
	}
	
	function calcPrice(){
		var v1 = ((cw*ch*2)+(cd*ch*2)+(cw*cd*2))/1000000;
		var price = ((24.35*v1+8*(cw+ch+cd)/1000+25.1+88*v1+((v1*mat[currMat][0])-(v1*mat[0][0])))/0.96);
		if (price < 70) price = 70;
		price = ((Math.round((price*1.72)*100))/100)*cq;
		var priceTxt = price.toString(10);
		if (priceTxt.indexOf(".") == -1) priceTxt = priceTxt + ".00";
		else{
			komma = priceTxt.substring(priceTxt.indexOf(".")+1,priceTxt.length);
			if (komma.length < 2) priceTxt = priceTxt + "0";
		}
		return priceTxt.replace(/\./,",");
	}
	
	function calulate(){
		if (CheckInputs() == true){
			d = document.calculateForm;
			cw = Number(d.calculateFormInputWidth.value);
			cd = Number(d.calculateFormInputDepth.value);
			ch = Number(d.calculateFormInputHeight.value);
			cq = Number(d.calculateFormInputQuantity.value);
			d.calculateFormResultFace.value = calcArea();
			d.calculateFormResultWeight.value = calcWeight();
			d.calculateFormResultPrice.value = calcPrice();
		}
	}