// JavaScript Document
//------------------------------------------------------------------------
// checkForm : checks each field for a given pattern of chars
function checkForm(frm){
	var pattern;
	// Utente (lettere, numeri, e i segni . _ -)
  	if(!checkMsg('messaggio',frm.messaggio.value,true))
  { 
    frm.messaggio.focus();
    return false; 
  }
	
	// E-mail  
	pattern = /^[a-zA-Z0-9._%-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;
	if(!checkPatternChars('email',frm.email.value,pattern,true))
  { 
    frm.email.focus();
    return false; 
  }
	  
  return true;
}

//------------------------------------------------------------------------
// checkPatternChars : checks a specific pattern of typed chars
function checkPatternChars(nm,vlu,pattern,required){
  if ( required === undefined ) {
      required = false;
   } 
  if(!required && vlu==""){
    return true;
  }
  if (!pattern.test(vlu)){
    alert("Il campo "+nm+" non e\' valido!");
    return false;
  }
  else { 
    return true; 
  }
}

function checkMsg (nm,vlu,required) {
	if ( required === undefined ) {
      required = false;
   }
   if(!required && vlu==""){
    return true;
  }
  if(required && vlu==""){
	alert("Il campo "+nm+" non e\' valido!");
    return false;
  }
  else { 
    return true; 
  }
}