function isValidEmail(id)
{
    var e = null;
    if( (id!=null) || (id==undefined) )
    	 e = document.getElementById(id);
    else
    	 e = document.getElementById('email');    
    
    var ok = true;
    //var filter=/^[A-Za-z][A-Za-z0-9_]*@[A-Za-z0-9_]+\.[A-Za-z0-9_.]+[A-za-z]$/;
    var filter=/^[A-Za-z]*[\.A-Za-z0-9_\-]*@[A-Za-z0-9_]+\.[A-Za-z0-9_.]+[A-za-z]$/; //bueno
    //var filter=/^([0-9a-zA-Z]([_.w]*[0-9a-zA-Z])*@([0-9a-zA-Z][-w]*[0-9a-zA-Z].)*([a-zA-Z]{2,9}.)+[a-zA-Z]{2,3})$/;
    
    if( e ) 
    {    
     	  if ( !filter.test( e.value )  )
     	  {
             	ok = false; 
	      }
    }
       
    /*
    
    if( !ok )
    {
        alert("- Email is needed or is incorrect.");           
        e.focus();
        return false;
    }
    
    */ 
                      
     return ok;
 }


function validateAsNumber(id)
{
	
	var e = document.getElementById(id);
	if(e)
	{
		if( isNaN(e.value) )
			return false;
	}
	return true;
}



function focusItem(id){
	 var e = document.getElementById(id);
	 if(e)
	    e.focus();
}


function isEmpty(id){
	var e = document.getElementById(id);
	if( e ){
		 if( e.value=='' )
			 return true;
	}
	
	return false;
}