function cent(amount) {
    // returns the amount in the .99 format
    amount -= 0;
    amount = Math.round(amount * 100)/100;
    return (amount == Math.floor(amount)) ? amount + '.00' : (  (amount*10 == Math.floor(amount*10)) ? amount + '0' : amount);
}


function calcPowerForField(field, skiptotal) {
    // <id> is something like "watt12"
    var cid = field.name.substr(4);
    var f = field.form;

// Piece-by-piece:	
//	    var cost =
//	        f.elements["watt"+cid].value / 1000 * // kw * 
//	        f.elements["utwk"+cid].value *        // units *
//	        f.elements["unit"+cid].options[f.elements["unit"+cid].selectedIndex].value *   // (min/week)/units *    // multiplying by "unit" field converts to min/week
//	        f.elements["usdperkwh"].value *                           // dollars/(kw * h) *
//	        365.25/7     / 60 * 100; // weeks/year *  h/min * cents/dollar

// Slightly "better"
    var cost =
	f.elements["watt"+cid].value * 
	f.elements["utwk"+cid].value *
	f.elements["unit"+cid].options[f.elements["unit"+cid].selectedIndex].value *
	f.elements["usdperkwh"].value * 36525/420000;

		// Some appliances are only on a fraction of the time that someone thinks
		// they're using it (e.g. refrigerator). So you can have a hidden field
		// whose value is a multiplier to the original value. (e.g. if it's 30% then
		// have a hidden field of name="cycleontime34" (or whatever), value="0.3"
		if (f.elements["cycleontime"+cid]) {
		    cost *= parseFloat(f.elements["cycleontime"+cid].value);
		}

    // Note cost is in cents

    var dmonth = 0, dyear = 0;
    if (!skiptotal) {
	dyear = (parseFloat(f["csyrtotal2"].value) || 0)  -
		 (parseFloat(f.elements["csyr"+cid].value) || 0);
	dmonth  = (parseFloat(f["csmototal2"].value) || 0) -
		 (parseFloat(f.elements["csmo"+cid].value) || 0);
    }

	if (f.elements["unit"+cid].options[f.elements["unit"+cid].selectedIndex].text == "months/year") {
	    f.elements["csmo"+cid].value = cent(Math.ceil(cost/f.elements["utwk"+cid].value || 0)/100);
	} else {
	    f.elements["csmo"+cid].value = cent(Math.ceil(cost/12 || 0)/100);
	}

    f.elements["csyr"+cid].value = cent(Math.ceil(cost || 0)/100);

    if (!skiptotal) {
	dmonth += parseFloat(f["csmo"+cid].value) || 0;
	dyear  += parseFloat(f["csyr"+cid].value) || 0;
	f["csyrtotal2"].value = cent(dyear);
	f["csmototal2"].value = cent(dmonth);
    }

}

function calcPowerCost(f) {
    // Calculates power costs for all fields of
    // form <f>.

    // Update cost fields
    var i=1,mototal=0,yrtotal=0;
    while(f["utwk"+i]) {
	if(f["utwk"+i].value != 0) {
	    calcPowerForField(f["utwk"+i], 1);
	    mototal += parseFloat(f["csmo"+i].value) || 0;
	    yrtotal += parseFloat(f["csyr"+i].value) || 0;
	}
	++i;
    }

    f["csmototal2"].value = cent(mototal);
    f["csyrtotal2"].value = cent(yrtotal);

}

/***********************************************
* Cool DHTML tooltip script II- © Dynamic Drive DHTML code library (www.dynamicdrive.com)
* This notice MUST stay intact for legal use
* Visit Dynamic Drive at http://www.dynamicdrive.com/ for full source code
***********************************************/

var offsetfromcursorX=12 //Customize x offset of tooltip
var offsetfromcursorY=-100 //Customize y offset of tooltip

var offsetdivfrompointerX=10 //Customize x offset of tooltip DIV relative to pointer image
var offsetdivfrompointerY=0 //Customize y offset of tooltip DIV relative to pointer image. Tip: Set it to (height_of_pointer_image-1).

document.write('<div id="dhtmltooltip"></div>') //write out tooltip DIV
document.write('<img id="dhtmlpointer" src="_img/arrow2.gif">') //write out pointer image

var ie=document.all
var ns6=document.getElementById && !document.all
var enabletip=false
if (ie||ns6)
var tipobj=document.all? document.all["dhtmltooltip"] : document.getElementById? document.getElementById("dhtmltooltip") : ""

var pointerobj=document.all? document.all["dhtmlpointer"] : document.getElementById? document.getElementById("dhtmlpointer") : ""

function ietruebody(){
return (document.compatMode && document.compatMode!="BackCompat")? document.documentElement : document.body
}

function ddrivetip(thetext, thewidth, thecolor){
if (ns6||ie){
if (typeof thewidth!="undefined") tipobj.style.width=thewidth+"px"
if (typeof thecolor!="undefined" && thecolor!="") tipobj.style.backgroundColor=thecolor
tipobj.innerHTML=thetext
enabletip=true
return false
}
}

function positiontip(e){
if (enabletip){
var nondefaultpos=false
var curX=(ns6)?e.pageX : event.clientX+ietruebody().scrollLeft;
var curY=(ns6)?e.pageY : event.clientY+ietruebody().scrollTop;
//Find out how close the mouse is to the corner of the window
var winwidth=ie&&!window.opera? ietruebody().clientWidth : window.innerWidth-20
var winheight=ie&&!window.opera? ietruebody().clientHeight : window.innerHeight-20

var rightedge=ie&&!window.opera? winwidth-event.clientX-offsetfromcursorX : winwidth-e.clientX-offsetfromcursorX
var bottomedge=ie&&!window.opera? winheight-event.clientY-offsetfromcursorY : winheight-e.clientY-offsetfromcursorY

var leftedge=(offsetfromcursorX<0)? offsetfromcursorX*(-1) : -1000

//if the horizontal distance isn't enough to accomodate the width of the context menu
if (rightedge<tipobj.offsetWidth){
//move the horizontal position of the menu to the left by it's width
tipobj.style.left=curX-tipobj.offsetWidth+"px"
nondefaultpos=true
}
else if (curX<leftedge)
tipobj.style.left="5px"
else{
//position the horizontal position of the menu where the mouse is positioned
tipobj.style.left=curX+offsetfromcursorX-offsetdivfrompointerX+"px"
pointerobj.style.left=curX+offsetfromcursorX+"px"
}

//same concept with the vertical position
if (bottomedge<tipobj.offsetHeight){
tipobj.style.top=curY-tipobj.offsetHeight-offsetfromcursorY+"px"
nondefaultpos=true
}
else{
tipobj.style.top=curY+offsetfromcursorY+offsetdivfrompointerY+"px"
pointerobj.style.top=curY+offsetfromcursorY+"px"
}
tipobj.style.visibility="visible"
if (!nondefaultpos)
pointerobj.style.visibility="hidden"
else
pointerobj.style.visibility="hidden"
}
}

function hideddrivetip(){
if (ns6||ie){
enabletip=false
tipobj.style.visibility="hidden"
pointerobj.style.visibility="hidden"
tipobj.style.left="-1000px"
tipobj.style.backgroundColor=''
tipobj.style.width=''
}
}

document.onmousemove=positiontip

