function CheckNumber(theNumber){
 var strLength, aCharacter, numberOffset, numberEncountered;
 numberOffset = 0;
 numberEncountered = false;
 strLength = theNumber.length;
 aCharacter = theNumber.substring(0, 1);
 if (theNumber.length==0) return false;
 if ((aCharacter == ".") || (aCharacter == ",") ||(aCharacter == "+") || (aCharacter == "-")) numberOffset = 1;
 aCharacter = theNumber.substring(numberOffset, numberOffset + 1);
 while ((aCharacter >= "0") && (aCharacter <= "9") && (numberOffset < strLength)){
  numberEncountered = true;
  aCharacter = theNumber.substring(++numberOffset, numberOffset + 1);
 }
 if (numberOffset == strLength) return(true);
 if (theNumber.substring(numberOffset, numberOffset + 1) == ".") {
  if (numberEncountered) numberOffset++;
  else return(false);
 }
 aCharacter = theNumber.substring(numberOffset, numberOffset + 1);
 while ((aCharacter >= "0") && (aCharacter <= "9") && (numberOffset < strLength))
  aCharacter = theNumber.substring(++numberOffset, numberOffset + 1);
 if (numberOffset == strLength) return(true);
 return(false);
}

function Arrondi( xNum ) {
 aNum = new String(xNum);
 var leret = "";
        var point = aNum.lastIndexOf('.', aNum.length);
        if (point == -1) leret = aNum + '.00';
 else {
         if (aNum.substring(0,1) == '.') leret = '0' + aNum;
  decimales = new String(aNum.substring(point+1, aNum.length));
  if (decimales.length == 1) leret = aNum + '0';
  else {
   if (decimales.length == 2) leret = aNum;
   else {
    troisieme_decimale = new String(decimales.substring(2, 3));
    if (troisieme_decimale < 5) leret = aNum.substring(0, point+1) + decimales.substring(0, 2);
    else {
     deux_dernieres_decimales = new String(decimales.substring(0, 2));
     plusun = new String((1 * deux_dernieres_decimales) + 1);
     if (plusun == 100) leret = new String((1 * aNum.substring(0, point))+ 1 ) + '.00';
     else {
      if (plusun.length == 1) leret = aNum.substring(0, point+1) + '0' + plusun;
      else leret = aNum.substring(0, point+1) + plusun;
     }
    }
   }
  }
 }
 return leret;
}

function Coma2Point(myVal) {
        var point = myVal.lastIndexOf(',', myVal.length);
 if (point != -1 ) myVal = myVal.substring(0, point ) + '.' + myVal.substring(point + 1, myVal.length);
 return myVal;
}


function CalcEuro(aform) {
 aform.inFr.value = Coma2Point(aform.inFr.value);
 aform.inEu.value = Coma2Point(aform.inEu.value);
 if ((aform.inFr.value.length == 0) && (CheckNumber(aform.inEu.value)))
  aform.inFr.value = Arrondi(aform.inEu.value * 9 / 5 + 32);
 else if (CheckNumber(aform.inFr.value)) 
  aform.inEu.value = Arrondi((aform.inFr.value -32)*5/9);
 else alert("Veuillez entrer un nombre !");
 return false;
}