function UnitConvertI(value,type){


				if(type=="cm")
					value = value/2.54;
				if(type=="m")
					value = (value*100)/2.54;
				if(type== "mm")
					value = (value/10)/2.54;



		return value;
		}
	function UnitConvertF(value,type){

				if(type== "cm")
					value = (value/2.54)/12;
				if(type =="m")
					value = ((value*100)/2.54)/12;
				if(type=="mm")
					value = ((value/10)/2.54)/12;


		return value;
		}
	function CheckNum(value,label){
			var String1 = new String(value);
			var String2 = new String("");
			var String3 = new String("");
			var String4 = new String("");
			var temp;
			var i=0;
			var count=0;
			for(i=0;i<String1.length;i++){
				String2 = new String(parseFloat(String1.charAt(i)));
				if(String1.charAt(i)==".")
					count++;

				if((String2.length!=1&&String1.charAt(i)!='.')||count>1){
					alert("You entered an illegal value for the " + label);
					return false;
				}
			}
			return true;
		}
	function CheckParam(Param1,Param2,Param3,Param4){
			var Form = document.forms[0].form.options[document.forms[0].form.selectedIndex].text;
			var valid1 = 0,valid2 = 0,valid3 = 0,valid4 = 0;
			var counter = 0;

				if(Form=="Lamina"){
				if(Param1==""||Param3==""||Param4 == ""||Param2==""){
					alert("Debes de escribir los valores de grosor, ancho y la longitud!");
					return false;
					}
					valid1 = CheckNum(Param1,"Grosor");
					valid2 = CheckNum(Param2,"Ancho");
					valid3 = CheckNum(Param3,"Longitud");
					valid4 = CheckNum(Param4,"No. de Piezas");
					if(valid1!=true||valid3!=true||valid4!=true||valid2!=true)
						return false;

				}
				if(Form=="Alambre_Redondo"){
					if(Param1==""||Param3==""||Param4 == ""){
					alert("Debes de escribir los valores del diametro y la longitud!");
					return false;
					}
					valid1 = CheckNum(Param1,"Diametro");
					valid3 = CheckNum(Param3,"Longitud");
					valid4 = CheckNum(Param4,"No. de Piezas");
					if(valid1!=true||valid3!=true||valid4!=true)
						return false;
				}
				if(Form=="Tubo"){
				if(Param1==""||Param3==""||Param4 == ""||Param2==""){
					alert("Debes de escribir los valores del diametro externo, la pared y la longitud!");
					return false;
					}
					valid1 = CheckNum(Param1,"Diametro Externo");
					valid2 = CheckNum(Param2,"Pared");
					valid3 = CheckNum(Param3,"Longitud");
					valid4 = CheckNum(Param4,"No. de Piezas");
					if(valid1!=true||valid2!=true||valid3!=true||valid4!=true)
						return false;

				}

			return true;
		}
	function CalculateWeight(){

			var Param = new Array(5);
			var Units = new Array(4);
			var Convert;
			var FormType;
			var Result;
			var Good;
			var ConvertW;
						
			Param[0] = document.forms[0].param1.value;
			Param[1] = document.forms[0].param2.value;
			Param[2] = document.forms[0].param3.value;
			Param[3] = document.forms[0].param4.value;
			Good = CheckParam(Param[0],Param[1],Param[2],Param[3]);
			if(!Good)
				return;


			Units[0] = document.forms[0].units1.options[document.forms[0].units1.selectedIndex].text;
			Units[1] = document.forms[0].units2.options[document.forms[0].units2.selectedIndex].text;
			Units[2] = document.forms[0].units3.options[document.forms[0].units3.selectedIndex].text;

			Param[0] = UnitConvertI(Param[0],Units[0]);
			Param[1] = UnitConvertI(Param[1],Units[1]);
			Param[2] = UnitConvertF(Param[2],Units[2]);

			FormType = document.forms[0].form.options[document.forms[0].form.selectedIndex].text;
						
			if(document.forms[0].product.selectedIndex>0)
				Convert = Factor[document.forms[0].product.selectedIndex-1];
			else
				Convert = 1.3249;
						
			if(document.forms[0].unitsW.selectedIndex>0)
			ConvertW = FactorW[document.forms[0].unitsW.selectedIndex];
			else
			ConvertW = 453.59237
					
			document.forms[0].result.rsize = "4";

				if(FormType=="Lamina"||FormType=="Placa"){
					Result = new String(3.4032 * Param[0] * Convert * ConvertW * Param[1] * Param[2] * Param[3]);
					document.forms[0].result.value = Result.substring(0,Result.indexOf(".")+RoundOff);
				}
				if(FormType=="Alambre_Redondo"){
					Result = new String(2.6729 * Param[0] * Param[0] * Convert * ConvertW * Param[2] * Param[3]);
					document.forms[0].result.value = Result.substring(0,Result.indexOf(".")+RoundOff);
				}
				if(FormType=="Tubo"){
					Result = 10.68 * (Param[0] - Param[1]) * Convert * ConvertW * Param[1] * Param[2] * Param[3];
					if(Result<0)
						alert("El ancho de la pared del tubo no puede ser mayor al diametro externo!");
					else{
					Result = new String(Result);
					document.forms[0].result.value = Result.substring(0,Result.indexOf(".")+RoundOff);
					}
				}
	}
	function ClearFields(){
		document.forms[0].param1.value = "";
		document.forms[0].param2.value = "";
		document.forms[0].param3.value = "";
		document.forms[0].param4.value = "1";
		document.forms[0].result.value = "";

		}
	function ChangeLabel(){
		var formType;
		formType = document.forms[0].form.options[document.forms[0].form.selectedIndex].text;


		if(formType=="Lamina"){
			document.forms[0].lbl1.value = "Grosor:";
			document.forms[0].lbl2.value = "Ancho:";
			document.forms[0].lbl3.value = "Longitud:";
			}
		if(formType=="Alambre_Redondo"){
			document.forms[0].lbl1.value = "Diametro:";
			document.forms[0].lbl2.value = "";
			document.forms[0].lbl3.value = "Longitud:";
			}
		if(formType=="Tubo"){
			document.forms[0].lbl1.value = "Diametro Externo:";
			document.forms[0].lbl2.value = "Pared:";
			document.forms[0].lbl3.value = "Longitud:";
			}

	}