<!--
var stparr = null;
var stpno = 0;
var eqstr = "";
var eqstps = "";

var divtmpl = "<table border=0><tr><td><table border=0 cellspacing=1 cellpadding=1><tr><td class=FRACLS rowspan=4>WHLNUM&nbsp;</td></tr><tr><td class=FRACLS style='text-align:center;'>NMRTR</td></tr><tr><td class=FRACLS height=2><img src='images/ydot.jpg' height=2 width=100%></td></tr><tr><td class=FRACLS style='text-align:center;'>DNMRTR</td></tr></table></td><td class=FRACLS>RHSEQ</td></tr></table>";
var multmpl = "<table border=0 cellspacing=1 cellpadding=1><tr><td class=FRACLS style='text-align:center;'>NMRTR</td></tr><tr><td class=FRACLS height=2><img src='images/ydot.jpg' height=2 width=100%></td></tr><tr><td class=FRACLS style='text-align:center;'>DNMRTR</td></tr></table>";

function setOptype(opc)
{
    if (opc != null) {opr = opc.options[opc.selectedIndex].value;}
}

function setVrbl(opc)
{
    if (opc != null) {vrbl = opc.options[opc.selectedIndex].value;}
}

function setDeci(opc)
{
    if (opc != null) {usedeci = opc.checked;}
}

function setNeg(opc)
{
    if (opc != null) {useneg = opc.checked;}
}

function setEq()
{
    var elm = document.getElementById("eqn");
    if (elm != null) {elm.innerHTML = eqstr;}
    stparr = eqstps.split("|");
    stpno = 0;
    elm = document.getElementById("eqstp");
    if (elm != null) {elm.innerHTML = "";}
}

function showStep()
{
    if (stparr.length > stpno)
    {
        var elm = document.getElementById("eqstp");
        if (elm != null) {var chld = elm.appendChild(document.createElement('div')); if (chld != null) {chld.innerHTML = stparr[stpno]}}
    }
    stpno++;
}

function showNew()
{
    var op = opr;
    if (op == 5) {op = getrand(1,4);}
    if (op == 2) {setSub();}
    else if (op == 3) {setMult();}
    else if (op == 4) {setDiv();}
    else {setAdd();}
    setEq();
}

function roundme(x) {return Math.round(x*100)/100;}

function setAdd()
{
    var rn1 = getrand(1,20);
    var rn2 = getrand(1,20); if (useneg && getrand(1,10)%2 == 1) {rn2 *= -1;}
    if (usedeci) {if (getrand(1,10)%2 == 1) {rn1 = rn1/10.0;};  if (getrand(1,10)%2 == 1) {rn2=rn2/10.0;}}
    eqstr = vrbl + " + " + rn1 + " = " + rn2;
    eqstps = "<span class=ylw>1. Subtract " + rn1 + " from both sides.</span>";
    eqstps = eqstps + "|" + vrbl + " + " + rn1 + "<span class=stp> - " + rn1 + "</span> = " + rn2 + "<span class=stp> - " + rn1 + "</span>";
    eqstps = eqstps + "|" + "<span class=ylw>2. Simplify.</span>";
    eqstps += "|" + vrbl + "<span class=stp> + 0 </span>= " + rn2 + "<span class=stp> - " + rn1 + "</span>";
    eqstps += "|" + vrbl + "  = " + roundme(rn2-rn1);
}

function setSub()
{
    var rn1 = getrand(1,20);
    var rn2 = getrand(1,20);if (useneg && getrand(1,10)%2 == 1) {rn2 *= -1;}
    if (usedeci) {if (getrand(1,10)%2 == 1) {rn1 = rn1/10.0;};  if (getrand(1,10)%2 == 1) {rn2=rn2/10.0;}}
    eqstr = vrbl + " - " + rn1 + " = " + rn2;
    eqstps = "<span class=ylw>1. add " + rn1 + " on both sides.</span>";
    eqstps += "|" + vrbl + " - " + rn1 + "<span class=stp> + " + rn1 + "</span> = " + rn2 + "<span class=stp> + " + rn1 + "</span>";
    eqstps = eqstps + "|" + "<span class=ylw>2. Simplify.</span>";
    eqstps += "|" + vrbl + "<span class=stp> - 0 </span>= " + rn2 + "<span class=stp> + " + rn1 + "</span>";
    eqstps += "|" + vrbl + "  = " + roundme(rn2+rn1);
}

function setMult()
{
    var rn1 = getrand(2,20);
    var rn2 = getrand(2,20);
    if (useneg && getrand(1,10)%2 == 1) {if (getrand(1,10)%2 == 1) {rn1 *= -1;} else {rn2 *= -1;}}
    if (usedeci) {if (getrand(1,10)%2 == 1) {rn1 = rn1/10.0;};  if (getrand(1,10)%2 == 1) {rn2=rn2/10.0;}}
    var res = Math.round(rn1 * rn2 * 100)/100;
    eqstr = rn1 + vrbl + " = " + res;
    var lhs = multmpl.replace(/FRACLS/g, "wht");
    lhs = lhs.replace("NMRTR", rn1 + vrbl);
    lhs = lhs.replace("DNMRTR", "<span class=stp>" + rn1 + "</span>");
    var rhs = multmpl.replace(/FRACLS/g, "wht");
    rhs = rhs.replace("NMRTR", res);
    rhs = rhs.replace("DNMRTR", "<span class=stp>" + rn1 + "</span>");
    eqstps = "<span class=ylw>1. Divide by " + rn1 + " on both sides.</span>";
    eqstps += "|<table border=0><tr><td>" + lhs + "</td><td class=wht>&nbsp;=&nbsp;</td><td>" + rhs + "</td></tr></table>";
    lhs = multmpl.replace(/FRACLS/g, "wht");
    lhs = lhs.replace("NMRTR", "<del>&nbsp;" + rn1 + "&nbsp;</del>" + vrbl);
    lhs = lhs.replace("DNMRTR", "<span class=stp><del>&nbsp;" + rn1 + "&nbsp;</del></span>");
    rhs = multmpl.replace(/FRACLS/g, "wht");
    rhs = rhs.replace("NMRTR", res);
    rhs = rhs.replace("DNMRTR", "<span class=stp>" + rn1 + "</span>");
    eqstps += "<span class=ylw>2. Simplify.</span>";
    eqstps += "|<table border=0><tr><td>" + lhs + "</td><td class=wht>&nbsp;=&nbsp;</td><td>" + rhs + "</td></tr></table>";
    eqstps += "|" + vrbl + "  = " + (rn2);
}

function setDiv()
{
    var rn1 = getrand(2,20);
    var rn2 = getrand(2,20);
    if (useneg && getrand(1,10)%2 == 1) {if (getrand(1,10)%2 == 1) {rn2 *= -1;}}
    if (usedeci) {if (getrand(1,10)%2 == 1) {rn1 = rn1/10.0;};  if (getrand(1,10)%2 == 1) {rn2=rn2/10.0;}}
    eqstr = divtmpl.replace("WHLNUM", "");
    eqstr = eqstr.replace(/FRACLS/g, "grn");
    eqstr = eqstr.replace("NMRTR", vrbl);
    eqstr = eqstr.replace("DNMRTR", rn1);
    eqstr = eqstr.replace("RHSEQ", " = " + rn2);
    eqstps = divtmpl.replace("WHLNUM", "<span class=stp>" + rn1 + " &times;</span>");
    eqstps = eqstps.replace(/FRACLS/g, "wht");
    eqstps = eqstps.replace("NMRTR", vrbl);
    eqstps = eqstps.replace("DNMRTR", rn1);
    eqstps = "<span class=ylw>1. multiply by " + rn1 + " on both sides.</span>|" + eqstps.replace("RHSEQ", " = <span class=stp>" + rn1 + " &times;</span> " + rn2);
    var stp2 = divtmpl.replace("WHLNUM", "<span class=stp><del>&nbsp;" + rn1 + "&nbsp;</del>&nbsp;&times;</span>");;
    stp2 = stp2.replace(/FRACLS/g, "wht");
    stp2 = stp2.replace("NMRTR", "&nbsp;" + vrbl);
    stp2 = stp2.replace("DNMRTR", "<del>&nbsp;" + rn1 + "&nbsp;</del>");
    stp2 = stp2.replace("RHSEQ", " = <span class=stp>" + rn1 + " &times;</span> " + rn2);
    eqstps = eqstps + "|" + "<span class=ylw>2. Simplify</span>|" + stp2;
    eqstps = eqstps + "|" + vrbl + " = " + Math.round((rn1*rn2)*100)/100;
}


function getrand(min, max)
{
  rnd = Math.floor(Math.random()*1000);
  rnd = rnd % (max-min+1);
  return min + rnd;
}

function getws(opr, vrbl, usedeci)
{
    var obj = document.getElementById("hdnvrbl");
    if (obj != null)
    {
        var chld = obj.appendChild(document.createElement('div')); 
        if (chld != null) {chld.innerHTML = "<input type=hidden name=opr value=" + opr + ">";}
        chld = obj.appendChild(document.createElement('div')); 
        if (chld != null) {chld.innerHTML = "<input type=hidden name=vrbl value=" + vrbl + ">";}
        chld = obj.appendChild(document.createElement('div')); 
        if (chld != null) {chld.innerHTML = "<input type=hidden name=usedeci value=" + (usedeci ? 1 : 0) + ">";}
        chld = obj.appendChild(document.createElement('div')); 
        if (chld != null) {chld.innerHTML = "<input type=hidden name=useneg value=" + (useneg ? 1 : 0) + ">";}
    }
    document.eqn1_frm.submit();
}


//-->

