function calcA() {
var a = parseFloat(document.RS.US.value);
if  ((a) &&  isNaN(a)) {
    alert("Not a valid number for a U.S.A. ring size");
    return;
    }
else {
    var d = 11.55 + 0.828*a ;
    mainCalc(d);
    }
}

function calcB() {
for( i = 0; i <=35 ; i++) {
    if( bsz[i] == document.RS.BR.value) {
        var d = 11.55 + 0.398*i ;
        break;
        }
    }

mainCalc(d);
}


function calcE() {
var e = parseFloat(document.RS.EU.value);
if  ((e) &&  isNaN(e)) {
    alert("Not a valid number for a European ring size");
    return;
    }
else {
    var d = (40 + e) / Math.PI ;
    mainCalc(d);
    }
}

function calcC() {
var c = parseFloat(document.RS.MC.value);
if  ((c) &&  isNaN(c)) {
    alert("Not a valid number ");
    return;
    }
else {
    var d = c / Math.PI ;
    mainCalc(d);
    }
}

function calcD() {
var d = parseFloat(document.RS.MD.value);
if  ((d) &&  isNaN(d)) {
    alert("Not a valid number for a European ring size");
    return;
    }
else { mainCalc(d) }
}

function mainCalc(d) {
var c = Math.PI * d ;
var e = c - 40 ;
var a = (d - 11.55) / 0.828
var j = (d - 38/3) * 3;
var b = (c - 36.3) * 0.8;
b = Math.round(40 * b );
var b1 = Math.floor(b/40);
var b2 = b % 40;
b2 = Math.round(b2/10);
var frac = "";
if (b2 == 4) {
	b1 = b1++ ;
    b3 = "";
}
else {
	if ( b2 == 1) { frac = " 1/4" };
    if ( b2 == 2) {frac = " 1/2" };
	if ( b2 == 3) {frac = " 3/4" };
    }

if ( b1<0 || b1>36 ) {b1 = 0 ; frac = "" }

document.RS.US.value =OneDP(a);
document.RS.MC.value =OneDP(c);
document.RS.MD.value =OneDP(d);
document.RS.EU.value = OneDP(e);
document.RS.BR.value = bsz[b1]+frac;
}

function OneDP(no) {
no = Math.round(10 * no);
var decno = no%10;
no = Math.floor(no/10);
var OutNo = no+"."+decno ;
if ( OutNo == "NaN.NaN") { OutNo="???"  }
if ( no < 0 || decno<0 )  { OutNo ="" }
return(OutNo);
}

function MakeArray(n) {
this.length =n;
for (var i = 1; i <= n; i++) { 
this[i] =0 }
return this
}

bsz = new MakeArray(37);
bsz[0] =  " "; bsz[1] = "A"; bsz[2] = "B"; bsz[3] = "C"; bsz[4] = "D"; bsz[5] = "E"; bsz[6] = "F";
bsz[7] = "G"; bsz[8] = "H"; bsz[9] = "I"; bsz[10] = "J"; bsz[11] = "K"; bsz[12] = "L"; bsz[13] = "M";
bsz[14] = "N"; bsz[15] = "O"; bsz[16] = "P"; bsz[17] = "Q"; bsz[18] = "R"; bsz[19] = "S"; bsz[20] = "T";
bsz[21] = "U"; bsz[22] = "V"; bsz[23] = "W"; bsz[24] = "X"; bsz[25] = "Y"; bsz[26] = "Z";
bsz[27] = "Z+1"; bsz[28] = "Z+2"; bsz[29] = "Z+3"; bsz[30] = "Z+4"; bsz[31] = "Z+5";
bsz[32] = "Z+6"; bsz[33] = "Z+7"; bsz[34] = "Z+8"; bsz[35] = "Z+9"; bsz[36] = "Z+10";


function closeWin(){
this.close();
}