/*
        Timma una stinga e aggiunge la funzionalità a String
*/
function trim(){
        tmp=this;
        while (tmp.substring(0,1) == ' '){
               tmp = tmp.substring(1, tmp.length);
        }
        while (tmp.substring(tmp.length-1, tmp.length) == ' ')
        {
               tmp = tmp.substring(0,tmp.length-1);
        }
        return tmp;
}

/*
        Controlla se una stringa è numerica
*/
function isNumeric(){
        var tmp=this;
        var ValidChars = "0123456789.";
        var IsNumber=true;
        var Char;
        for (i = 0; i < tmp.length && IsNumber == true; i++){
        Char = tmp.charAt(i);
               if (ValidChars.indexOf(Char) == -1){
                       IsNumber = false;
        }
    }
        return IsNumber;
}

/*
        Controlla se una stringa è mail valida
*/
function isMail(){
        var tmp=this;
        var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
        if(tmp.trim()=="")
               return true;

        if (filter.test(tmp))
               return true;
        else
               return false;
}

function replaceAll(findStr,repStr) {
        oldStr=this;
  var srchNdx = 0;  
  var newStr = "";  
  while (oldStr.indexOf(findStr,srchNdx) != -1)  {
    newStr += oldStr.substring(srchNdx,oldStr.indexOf(findStr,srchNdx));
    newStr += repStr;
    srchNdx = (oldStr.indexOf(findStr,srchNdx) + findStr.length);
  }
  newStr += oldStr.substring(srchNdx,oldStr.length);
  return newStr;
}





String.prototype.trim=trim;
String.prototype.isNumeric=isNumeric;
String.prototype.isMail=isMail;
String.prototype.replaceAll=replaceAll;