function ParseUSNumber(PhoneNumberInitialString) {     var FmtStr="";     var index = 0;     var LimitCheck; if (PhoneNumberInitialString == "") { return FmtStr; }     LimitCheck = PhoneNumberInitialString.length;     while (index != LimitCheck)       {         if (isNaN(parseInt(PhoneNumberInitialString.charAt(index))))           { }         else           { FmtStr = FmtStr + PhoneNumberInitialString.charAt(index); }         index = index + 1;       } if (FmtStr.length < 10)       { alert("Wait! You are missing a few digits in your\nphone number. Please check it and try again.\nFormat using U.S. area code and number\n\n (555) 555-5555");  } if (FmtStr.length > 10)       { alert("Wait! You are have entered too many digits\nin your phone number. Please check it and try again.\nFormat using U.S. area code and number\n\n (555) 555-5555");  }     if (FmtStr.length == 10)       {         FmtStr = "(" + FmtStr.substring(0,3) + ") " + FmtStr.substring(3,6) + "-" + FmtStr.substring(6,10);       }     else       {         FmtStr=PhoneNumberInitialString; }     return FmtStr;   }