function calculateBraSize( nRibSize, nBustSize ) {
    if ( nRibSize == '') {
      alert( "Please enter rib cage size" );
      return;
    }

    if ( nBustSize == '') {
      alert( "Please enter Chest + Breast Size" );
      return;
    }
    var cupSize;
    var bandSize = eval(nRibSize) + 5.0;
    bandSize = Math.round(bandSize);

    if ((bandSize % 2) != 0) {
      bandSize++;
    }
    var nDiff = nBustSize - bandSize;

    if (( nDiff >= 0 ) && ( nDiff < 0.5 )) {
      cupSize = "AA";
    } else if (( nDiff >= 0.5 ) && ( nDiff < 1.0 )) {
      cupSize = "A";
    } else if (( nDiff >= 1.0 ) && ( nDiff < 2.5 )) {
      cupSize = "B";
    } else if (( nDiff >= 2.5 ) && ( nDiff < 3.5 )) {
      cupSize = "C";
    } else if (( nDiff >= 3.5 ) && ( nDiff < 4.5 )) {
      cupSize = "D";
    } else if (( nDiff >= 4.5 ) && ( nDiff < 6.0 )) {
      cupSize = "DD (also known as E)";
    } else if (( nDiff >= 6.0 ) && ( nDiff < 7.0 )) {
      cupSize = "DDD (also known as F)";
    } else if (( nDiff >= 7.0 ) && ( nDiff < 8.0 )) {
      cupSize = "G";
    } else if ( nDiff >= 8.0 ) {
      cupSize = "H or larger.";
    } else {
      cupSize = "\nLucky Duck, you don't need a bra!";
    }
    var strMessage;
    strMessage = "Your recommended bra size is " + bandSize + " " + cupSize; 
    alert(strMessage);
    return;
  

}