//-------------------------------------------------------------------------    
//inductance value to colour translator function            
//modified from GRAPHICAL RESISTANCE CALCULATOR in JAVASCRIPT by Danny Goodman (dannyg@dannyg.com)                    
//Analyzed and described at length in                             
//"JavaScript Bible"                      
//(IDG Books ISBN 0-7645-3022-4)        
//This program is Copyright 1996 by Danny Goodman.  
//You may adapt this calculator for your Web pages, provided these opening credit    
//lines (down to the lower dividing line) are in your outliner HTML document.    
//You may not reprint or redistribute this code without permission from     
//the author.    ----------------------------------------------------------


// create array listing all the multiplier values

var multiplier = new Array()
multiplier[0] = 0
multiplier[1] = 1
multiplier[2] = 2
multiplier[3] = 3
multiplier[4] = 4
multiplier[5] = -1
multiplier[6] = -2

// create array listing all tolerance values

var tolerance = new Array()
tolerance[0] = "+/-5%"
tolerance[1] = "+/-10%"
tolerance[2] = "+/-20%"

// format values from microhenrys to micro, milli or henrys
function format(value) {
	if (value >= 1000) {
		value /= 1000
		return "" + value + " Millihenrys";}
	else {
		return "" + value + " Microhenrys";}
}

// calculate inductance and tolerance values
function calcValue() {
	var form = document.forms[0]
	var d1 = form.tensSelect.selectedIndex
	var d2 = form.onesSelect.selectedIndex
	var m = form.multiplierSelect.selectedIndex
	var t = form.toleranceSelect.selectedIndex
	var value = (d1 * 10) + d2
	value = eval("" + value + "e" + multiplier[m])
	value = format(value)
	var tol = tolerance[t]
	document.forms[1].result.value = value + ", " + tol
}

// pre-load all color images into image cache
var colorList = "Black,Blue,Brown,Gold,Grey,Green,None,Orange,Red,Silver,Violet,White,Yellow"
var colorArray = colorList.split(",")
var imageDB = new Array()
for (i = 0; i < colorArray.length; i++) {
	imageDB[colorArray[i]] = new Image(21,128)
	imageDB[colorArray[i]].src = "../images/calc/i" + colorArray[i] + ".gif"
}

function setTens(choice) {
	var tensColor = choice.options[choice.selectedIndex].text
	document.tens.src = imageDB[tensColor].src
	calcValue()
}
function setOnes(choice) {
	var onesColor = choice.options[choice.selectedIndex].text
	document.ones.src = imageDB[onesColor].src
	calcValue()
}
function setMult(choice) {
	var multColor = choice.options[choice.selectedIndex].text
	document.mult.src = imageDB[multColor].src
	calcValue()
}
function setTol(choice) {
	var tolColor = choice.options[choice.selectedIndex].text
	document.tol.src = imageDB[tolColor].src
	calcValue()
}


var form = document.forms[0]
var tensDigit = form.tensSelect.selectedIndex
var tensColor = form.tensSelect.options[tensDigit].text
var onesDigit = form.onesSelect.selectedIndex
var onesColor = form.onesSelect.options[onesDigit].text
var multDigit = form.multiplierSelect.selectedIndex
var multColor = form.multiplierSelect.options[multDigit].text
var tolDigit = form.toleranceSelect.selectedIndex
var tolColor = form.toleranceSelect.options[tolDigit].text

var table = "<FORM action='javascript:void(0)'>Inductance:&nbsp;&nbsp;<INPUT TYPE='text' NAME='result' SIZE=20></FORM>" +
			"<br><IMG SRC='../images/calc/indleft.gif' WIDTH=127 HEIGHT=128>" +
			"<IMG SRC='../images/calc/i" + tensColor + ".gif' NAME='tens' WIDTH=21 HEIGHT=128>"+
			"<IMG SRC='../images/calc/i" + onesColor + ".gif' NAME='ones' WIDTH=21 HEIGHT=128>"+
			"<IMG SRC='../images/calc/i" + multColor + ".gif' NAME='mult' WIDTH=21 HEIGHT=128>"+
			"<IMG SRC='../images/calc/ispacer.gif' WIDTH=17 HEIGHT=128>"+
			"<IMG SRC='../images/calc/i" + tolColor + ".gif' NAME='tol' WIDTH=21 HEIGHT=128>"+
			"<IMG SRC='../images/calc/indright.gif' WIDTH=127 HEIGHT=128>"