/* Copyright 2006 Greg Posel          */
/* calc.js - Updated 04/11/06 */

function selectWeight()
{
	if (document.refCalculator.materialBox.selectedIndex > 2)
	{
		document.refCalculator.measureBox.selectedIndex = 1;
	}
}

function checknGo()
{
	if (validateEntries())
	    calcValue();
}

function printValue(subtractor, factor)
{
	var wFloat = 0;
	var mFloat = 0;
	var answer = 0;
	var weight = document.refCalculator.weightBox.value;
	var market = getSelection(document.refCalculator.spotBox.innerHTML);
	
	wFloat = parseFloat(weight);
	mFloat = parseFloat(market);
	answer = factor * wFloat * (mFloat - subtractor);
	answer = formatAnswer(answer);
	//display value
	document.refCalculator.valueBox.value = answer;
}

function getSelection(selection)
{
	var posFound;
	var newSelection;
	
	posFound     = selection.search("selected>");
	newSelection = selection.substring(posFound + 9, posFound + 13);
	
	return(newSelection);
}

function formatAnswer(answer)
{
	var fmtStg = "";
	var i, stop;
	
	answer *= 100;
	answer = Math.round(answer);
	answer = answer.toString();
	stop   = answer.length;
	
	for (i = 1; i <= stop; i++)
	{
		fmtStg += answer.substring(stop - i, stop - i + 1);
		if (i == 2)
		{
			fmtStg += ".";
		}
		else if (i == 5 || i == 8 || i == 11)
		{
			if ( i != stop ) fmtStg += ",";
		}
	}
	fmtStg += " $ ";
	answer = "";
	stop = fmtStg.length;
	
	for (i = 1; i <= stop; i++)
	{
		answer += fmtStg.substring(stop - i, stop - i + 1);
	}
	return (answer);
}

function calcValue()
{
	var measure    = document.refCalculator.measureBox.selectedIndex;
	var factor     = 0;
	var subtractor = 0;
	
	switch(document.refCalculator.materialBox.selectedIndex)
	{
		case 0:
		{
			// alert("Silver Flake Selected");
			subtractor = .15;
			if (measure == 0) // Troy Ounces
			{
				factor     = .85; 
			}
			else if(measure == 1) // Pounds
			{
				factor     = 12;
			}
			else // Grams
			{
				factor     = .032154 * .85;
			}
			break;
		}
		case 1:
		{
			// alert(".999 Silver Selected");
			subtractor = .20;
			if (measure == 0) // Troy Ounces
			{
				factor = 1;
			}
			else if (measure == 1) // Pounds
			{
				factor = 14.583;
			}
			else // Grams
			{
				factor = .032154;
			}
			break;
		}
		case 2:
		{
			// alert("Sterling Selected");
			subtractor = .15;

			if (measure == 0) // Troy Ounces
			{
				factor = .88 * .9;
			}
			else if (measure == 1) // Pounds
			{
				factor = 14.583 * .88 * .9;
			}
			else // Grams
			{
				factor = .032154 * .88 * .9;
			}
			break;
		}
		case 3:
		{
			// alert("X-Ray Selected");
			subtractor = .15;
	
			if (measure != 1)
			{
				alert("Film weights must be measured in pounds!");
			}
			else
			{
				factor = .015;
			}
			break;
		}
		case 4:
		{
			// alert("Industrial X-Ray Selected");
			subtractor = .15;
			
			if (measure != 1)
			{
				alert("Film weights must be measured in pounds!");
			}
			else
			{
				factor = .18;
			}
			break;
		}
		case 5:
		{
			// alert("Scans Selected");
			subtractor = .15;
			
			if (measure != 1)
			{
				alert("Film weights must be measured in pounds!");
			}
			else
			{
				factor = .005;
			}
			break;
		}
		case 6:
		{
			// alert("Newspaper Litho Selected");
			subtractor = .15;
			
			if (measure != 1)
			{
				alert("Film weights must be measured in pounds!");
			}
			else
			{
				factor = .13;
			}
			break;
		}
		case 7:
		{
			// alert("Mix Litho Selected");
			subtractor = .15;
			
			if (measure != 1)
			{
				alert("Film weights must be measured in pounds!");
			}
			else
			{
				factor = .15;		}
			break;
		}
		default:
		{
			alert("No Handler");
		}
	}
	printValue(subtractor,factor);
}


function validateEntries()
{
  var theForm = document.refCalculator
  var checkOK = "0123456789-.,";
  var checkStr = theForm.weightBox.value;
  var allValid = true;
  var decPoints = 0;
  var allNum = "";
  for (i = 0;  i < checkStr.length;  i++)
  {
    ch = checkStr.charAt(i);
    for (j = 0;  j < checkOK.length;  j++)
      if (ch == checkOK.charAt(j))
        break;
    if (j == checkOK.length)
    {
      allValid = false;
      break;
    }
    if (ch == ".")
    {
      allNum += ".";
      decPoints++;
    }
    else if (ch != ",")
      allNum += ch;
  }
  if (!allValid)
  {
    alert("Please enter only digit characters in the Weight field.");
    theForm.weightBox.focus();
    return (false);
  }

  if (decPoints > 1)
  {
    alert("Please enter a valid number in the Weight field.");
    theForm.weightBox.focus();
    return (false);
  }

  var chkVal = allNum;
  var prsVal = parseFloat(allNum);
  if (chkVal != "" && !(prsVal > "0"))
  {
    alert("Please enter a value greater than 0 in the Weight field.");
    theForm.weightBox.focus();
    return (false);
  }
  return (true);
}