function verifica(form) {

var totalescelte = 0;
var k = 0;

if(trim(form.codice.value) == "") 
{
    alert("Il codice e' un dato obbligatorio.");
    form.codice.focus();
    return(false);
}

if(trim(form.email.value) != "") {

 if(isEmail(form.email.value) == false || form.email.value.indexOf(" ") != -1) {
   alert("L'indirizzo e-mail indicato non e' corretto.");
   form.email.focus();
   return(false);
 }
}


return(true);
}

function trim(inputString) {
   // Removes leading and trailing spaces from the passed string. Also removes
   // consecutive spaces and replaces it with one space. If something besides
   // a string is passed in (null, custom object, etc.) then return the input.
   if (typeof inputString != "string") { return inputString; }
   var retValue = inputString;
   var ch = retValue.substring(0, 1);
   while (ch == " ") { // Check for spaces at the beginning of the string
      retValue = retValue.substring(1, retValue.length);
      ch = retValue.substring(0, 1);
   }
   ch = retValue.substring(retValue.length-1, retValue.length);
   while (ch == " ") { // Check for spaces at the end of the string
      retValue = retValue.substring(0, retValue.length-1);
      ch = retValue.substring(retValue.length-1, retValue.length);
   }
   while (retValue.indexOf("  ") != -1) { // Note that there are two spaces in the string - look for multiple spaces within the string
      retValue = retValue.substring(0, retValue.indexOf("  ")) + retValue.substring(retValue.indexOf("  ")+1, retValue.length); // Again, there are two spaces in each of the strings
   }
   return retValue; // Return the trimmed string back to the user
} // Ends the "trim" function

function isEmail(str) {
  // are regular expressions supported?
  var supported = 0;
  if (window.RegExp) {
    var tempStr = "a";
    var tempReg = new RegExp(tempStr);
    if (tempReg.test(tempStr)) supported = 1;
  }
  if (!supported) 
    return (str.indexOf(".") > 2) && (str.indexOf("@") > 0);
  var r1 = new RegExp("(@.*@)|(\\.\\.)|(@\\.)|(^\\.)");
  var r2 = new RegExp("^.+\\@(\\[?)[a-zA-Z0-9\\-\\.]+\\.([a-zA-Z]{2,4}|[0-9]{1,4})(\\]?)$");
  return (!r1.test(str) && r2.test(str));
}