function browserID(){
 	if (navigator.userAgent.indexOf("Opera")!=-1
	    && document.getElementById) type="OP";
	if (document.all) type="IE";
	if (document.layers) type="NN";
	if (!document.all && document.getElementById) type="MO"; 
}

function dynamicHTML(id, str) {
  browserID();
  if (type=="IE") {
    document.all[id].innerHTML = str;
  }
  if (type=="NN") {
    document.layers[id].document.open();
    document.layers[id].document.write(str);
    document.layers[id].document.close();
  }
  if (type=="MO" || type=="OP") {
    document.getElementById(id).innerHTML = str;
  }
}

function IsEmpty(aTextField) {
   if ((aTextField.value.length==0) ||
   (aTextField.value==null)) {
      return true;
   }
   else { return false; }
}	

function ValidateNumeric(aTextField) {
if (!IsNumeric(form.account_number.value)) 
   { 
      alert('Please enter only numbers or decimal points in the account field') 
      form.account_number.focus(); 
      return false; 
      } 
else { return true;}
}
 
function deltalength(form) {
	
	if(IsEmpty(form.length)) 
	   { 
	      alert('You have not entered an pipe length') 
	      form.account_number.focus(); 
	      return false; 
	   } 
	else if(IsEmpty(form.deltatemp)) 
	   { 
	      alert('You have not entered a change in temperature') 
	      form.account_number.focus(); 
	      return false; 
	   } 
	else {
	
		a = eval(form.length.value);
		b=eval(form.deltatemp.value);
		c = (0.1422 * a * b);
		answer = Math.round(c*10)/10;
		form.ans1.value = answer;
	}
}

function calcmaxflow(form) {
	selectedPipe = form.PipeType.selectedIndex;
	diameter = form.PipeType.options[selectedPipe].value;
	pi = 3.141592654;
	if (diameter != "none") {
	answer = Math.pow((diameter/1000),2)/4*1000*pi*180;
	form.Lmin.value = Math.round(answer*10)/10;
	form.Lsec.value = Math.round(answer/6)/10;
	}
	else {
		form.Lmin.value="";
		form.Lsec.value="";
	}
}

function tubePressureLoss(form) {
	selectedPipe = form.PipeType.selectedIndex;
	PipeText = form.PipeType.options[selectedPipe].value;
	if (selectedPipe == 0) {
		PressureLossArray=new Array("0","0","0","0","0");
	}
	else if (selectedPipe == 1) {
		PressureLossArray=new Array("0","0.98","3.54","7.51","12.80","19.35");
	}
	else if (selectedPipe == 2) {
		PressureLossArray=new Array("0","0.28","1.02","2.17","3.70","5.59");
	}
	else if (selectedPipe == 3) {
		PressureLossArray=new Array("0","0.09","0.32","0.68","1.16","1.76");
	}
	selectedFlow = form.FlowRate.selectedIndex;
	FlowText = form.FlowRate.options[selectedFlow].value;
	if (selectedFlow != 0) {
		answer = PressureLossArray[selectedFlow] * form.PipeLength.value;
		form.ans1.value = Math.round(answer*Math.pow(10,2))/Math.pow(10,2);
	}
}

function changePipeType(form) {
	selectedPipe = form.PipeType.selectedIndex;
	PipeText = form.PipeType.options[selectedPipe].value;
	if (selectedPipe == 0) {
		stringtext = "To comply with AS3500, maximum velocity in pipe is 3m/s.";		
	}
	else if (selectedPipe == 1) {
		stringtext = "Maximum flow rate for this size pipe to meet AS3500 is 0.3 L/sec.";		
	}
	else if (selectedPipe == 2) {
		stringtext = "Maximum flow rate for this size pipe to meet AS3500 is 0.5 L/sec.";			
	}
	else if (selectedPipe == 3) {
		stringtext = "Maximum flow rate for this size pipe to meet AS3500 is 0.9 L/sec.";		
	}
	dynamicHTML("PipeInformation",stringtext);
}

function tubePressureLoss1(form) {
	if(!IsEmpty(form.FlowRate)) {
		selectedPipe = form.PipeType.selectedIndex;
		flowrate= form.FlowRate.value;
		PipeLength = form.PipeLength.value;
		HazWil = 150;
		ConversionConst = 9.7968505;
		if (selectedPipe != 0) {
			InternalDiameter = form.PipeType.options[selectedPipe].value;
		} else InternalDiameter = "";
		answer = PipeLength * Math.pow((100/HazWil),1.852)*Math.pow((15.85032*flowrate),1.852)/Math.pow((InternalDiameter/25.4),4.8655)*0.2083*ConversionConst/100
		form.ans1.value = Math.round(answer*Math.pow(10,2))/Math.pow(10,2);
	}	 
}

function tubePressureLoss2(form) {

	for (var i=0; i < document.PressureLossTube2.InternalDiameter.length; i++)
	   {
	   if ( document.PressureLossTube2.InternalDiameter[i].checked)
	      {
	      var InternalDiameter =  document.PressureLossTube2.InternalDiameter[i].value;
	      }
	   }

	flowrate= form.FlowRate.value;
	PipeLength = form.PipeLength.value;
	HazWil = 150;
		ConversionConst = 9.7968505;
		answer = PipeLength * Math.pow((100/HazWil),1.852)*Math.pow((15.85032*flowrate/60),1.852)/Math.pow((InternalDiameter/25.4),4.8655)*0.2083*ConversionConst/100
		form.ans1.value = Math.round(answer*Math.pow(10,2))/Math.pow(10,2);
	
	
}
function fittingloss(form) {
	for (var i=0; i < document.FittingLoss.InternalDiameter.length; i++)
	   {
	   if ( document.FittingLoss.InternalDiameter[i].checked)
	      {
	      var InternalDiameter =  document.FittingLoss.InternalDiameter[i].value;
	      }
	   }
	for (var i=0; i < document.FittingLoss.Fitting.length; i++)
	   {
	   if ( document.FittingLoss.Fitting[i].checked)
	      {
	      var straightconst =  document.FittingLoss.Fitting[i].value;
	      }
	   }
	if(!IsEmpty(form.FlowRate)) {
		flowrate= form.FlowRate.value;
		pi = 3.141592654;
		answer = straightconst * Math.pow((flowrate/60/1000/(pi*Math.pow((InternalDiameter/1000),2)/4)),2)/(2*9.81);
		form.ans1.value = Math.round(answer*Math.pow(10,2))/Math.pow(10,2);
	}	 
}
function calcElbowloss(form) {
	if(!IsEmpty(form.FlowRate)) {
		selectedPipe = form.PipeType.selectedIndex;
		straightconst = 30;
		flowrate= form.FlowRate.value;
		HazWil = 150;
		pi = 3.141592654;
		if (selectedPipe != 0) {
			InternalDiameter = form.PipeType.options[selectedPipe].value;
		} else InternalDiameter = "";
		answer =straightconst * Math.pow( (flowrate/1000/ (pi* Math.pow( (InternalDiameter/1000) ,2) /4 )), 2) / (2*9.81);
		form.ans1.value = Math.round(answer*Math.pow(10,2))/Math.pow(10,2);
	}	 
}

function calcStraightloss(form) {
	if(!IsEmpty(form.FlowRate)) {
		selectedPipe = form.PipeType.selectedIndex;
		straightconst = 9;
		flowrate= form.FlowRate.value;
		HazWil = 150;
		pi = 3.141592654;
		if (selectedPipe != 0) {
			InternalDiameter = form.PipeType.options[selectedPipe].value;
		} else InternalDiameter = "";
		answer =straightconst * Math.pow((flowrate/1000/(pi*Math.pow((InternalDiameter/1000),2)/4)),2)/(2*9.81);
		form.ans1.value = Math.round(answer*Math.pow(10,2))/Math.pow(10,2);
	}	 
}


function calcVelocity(form) {
	if(!IsEmpty(form.FlowRate)) {
		selectedPipe = form.PipeType.selectedIndex;
		flowrate = form.FlowRate.value;
		pi = 3.141592654;
		if (selectedPipe != 0) {
			InternalDiameter = form.PipeType.options[selectedPipe].value;
		} 
		answer = (flowrate/1000) / (pi * Math.pow((InternalDiameter/1000),2)/4)/60;
		form.ans1.value = Math.round(answer*Math.pow(10,2))/Math.pow(10,2);
	}	 
}