<!--


 function app_comments()
  {
   zfr_comments('Hazen-Williams Equation');
  }

 function app_about()
  {
   var MSG = "<br><center><b>Hazen-Williams Equation</b>";
   MSG+="<br>Pipes pressure drop calculation<br><br>(c) 2006-2008 Zonum Solutions</center>";
   zwin_msgbox("About",300,110,"","",MSG);
  }
    
 
   function getrandom()
   {
    return Math.floor(Math.random()*100)
   }
   
  function get_new_winname()
	 {
	  var win_name = "hw"+getrandom()+"_"+getrandom()+"_"+getrandom();
	  //alert("Window Name = "+win_name);
	  return win_name
	 } 
   
  function get_module_url(xmodule)
	{
	 var url = "hazen_williams_eq.php";
	 if(xmodule!=0) {
	   url+= "?id="+xmodule;
	   if(zUnits!="in") { url+="&units="+zUnits;}
	  }
	  
	 return url 
	} 
   
  function open_newwindow(url,props)
	 {
	  // alert("url="+url);
	   var  myWin = window.open(url,get_new_winname(),props);
       if(myWin) {
         if (myWin.focus) {myWin.focus();} 
       }
	 } 
   
  function app_option(n,newpage)
   {
    var url=get_module_url(n);
    if(newpage==true) {
       open_newwindow(url,"width=750,height=640,scrollbars=no,resizable=yes");
    } else {window.location=url}
   }

  function app_openmini()
   {
    open_newwindow(get_module_url(zModule)+"&mini=true","width=470,height=255,scrollbars=no,resizable=yes");
   }


  function app_update_units()
   {
    var xunits = zweb_listIndex(document.frData.funits);
    if(xunits==0) {zUnits="SI";
    } else {zUnits="CU";}
    
    app_process(false);
   }
   
   
   
	function getunits_label(index,isEnglish)
	 {
	   var ulabel="unknown";
	   if(isEnglish==true) {ulabel=units_cu[index];}
	    else {ulabel=units_si[index];}
	   return ulabel
	 }    
   
   
  function app_getunits_label(category)
	 {
	  var isEnglish=true;
	  if(zUnits=="SI") {isEnglish=false;}
	  var ulabel="unknown";
	  switch (category) {
	   case "pd": ulabel=getunits_label(0,isEnglish); break;
		 case "q": ulabel=getunits_label(1,isEnglish); break;
		 case "d": ulabel=getunits_label(2,isEnglish); break;
	  }
	  return ulabel
	 } 
   
 
  function app_update()
   {app_process(false);}
 
  function app_calculate()
   {app_process(true);}
   
   
  function get_CNTable(idobj)
	{
	  alert("Not Ready");
	} 
   
   
  function get_statusbar()
	 {
	  var stbar="&copy; 2006-2008 Zonums&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;";
	  var stlinks = '<a href="javascript:zfr_disclaimer();">Disclaimer</a>&nbsp;&nbsp;&nbsp;<a href="javascript:app_about();">About</a>';
	  if (isMini=="true") {
	   stbar +=stlinks;
	  } else {
	    stbar +='&nbsp;&nbsp;&nbsp;&nbsp;<a href="javascript:app_comments();">Comments</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;';
	    stbar +=stlinks;
	  }
	  
	  return stbar
	 } 
   
  function set_appbar(msg,isAlert)
	 {
	  var obj = document.getElementById("appstatusbar");
	  if (msg=="") {msg=get_statusbar();}
	  if(isAlert) {
		  obj.style.background = "red";
		  obj.style.color = "yellow";
			} else {
		   obj.style.background = "#ece9d8";
			 obj.style.color = "black";
			}
	  obj.innerHTML="<center>"+msg+"</center>";
	 } 
	 
	function app_resetstatusbar()
	 {set_appbar('',false);} 
   
  function app_mainonload()
  {
   app_resetstatusbar();
   clear_allvalues();
   app_update_units();
   app_onload();
  }
	 
	 
	function checkinput_status(xstate,valueWrong,MsgLabel)
  {
   if(xstate==true) {
     if(valueWrong==true) {
        set_appbar(MsgLabel,true);
        xstate = false;
      }
   }
   return xstate
  } 
	 
   
 //calculations
 
 function get_pd(Q,C,D,isEnglish)
  {
   var pd=0;
   if(isEnglish==false) {
    pd= 1.1101*Math.pow(10,10)*Math.pow(Q/C,1.85)*1/(Math.pow(D,4.87));
   } else {
    pd =4.524*Math.pow(Q/C,1.85)*1/(Math.pow(D,4.87));
   }
  
   return pd
  }
   
  function get_q(pd,C,D,isEnglish)
  {
   var q=0;
   var xvalue=0;
   if(isEnglish==false) {
    xvalue= 1.1101*Math.pow(10,10)*1/Math.pow(C,1.85)*1/(Math.pow(D,4.87));
    q=Math.pow(pd/xvalue,1/1.85);
   } else {
    xvalue =4.524*1/Math.pow(C,1.85)*1/(Math.pow(D,4.87));
    q=Math.pow(pd/xvalue,1/1.85);
   }
  
   return q
  } 
   
   
  function get_d(pd,Q,C,isEnglish)
  {
   var d=0;
   
   if(isEnglish==false) {
    d= (1.1101*Math.pow(10,10)*Math.pow(Q/C,1.85))/pd;
		d= Math.pow(d,1/4.87);
   } else {
    d =(4.524*Math.pow(Q/C,1.85))/pd;
		d=Math.pow(d,1/4.87);
   }
   return d
  } 
   
  function get_c(pd,Q,D,isEnglish)
  {
   var c=0;
   
   if(isEnglish==false) {
    c= (1.1101*Math.pow(10,10)*Math.pow(Q,1.85)*1/(Math.pow(D,4.87)))/pd;
		c= Math.pow(c,1/1.85);
   } else {
    c =(4.524*Math.pow(Q,1.85)*1/(Math.pow(D,4.87)))/pd;
		c=Math.pow(c,1/1.85);
   }
   return c
  } 
  



 //Http request
 function WebGet(Url,Id)
 { var xmlHttp;
    try
       {  // Firefox, Opera 8.0+, Safari 
			  xmlHttp=new XMLHttpRequest(); 
			 }
        catch (e)
       {  // Internet Explorer
			   try
           {    xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");    }
            catch (e)
            {    try
              {  xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");      }
                catch (e)
               { WebGet_Error(Id);
							   //alert("Your browser does not support AJAX!");  
							   return false; 
							  }
						 }
				}
      xmlHttp.onreadystatechange=function()
      {if(xmlHttp.readyState==4)
        {
         WebGet_Data(Id,xmlHttp.responseText);
        }
      }
   xmlHttp.open("GET",Url,true);
   xmlHttp.send(null);  
}




  //library calculations
  
  
  
  function edit_getval(editcontrol)
  {
   var value =0;

   if(editcontrol.value=="") {value =0;}
   else {value = parseFloat(editcontrol.value);}
   
   return value
 }

 
-->