function sinEspacios(obj)
{
    
    obj.keypress(function(e){
        
        if(e.which == 32)
        {
            return false;
        }
        
    });//obj.keypress(function(e){
    
}//sinEspacios

function soloNumeros(obj)
{
    
    obj.keypress(function(e){               
        
        if((e.which < 48 || e.which > 57))
        {
            if(!(e.which == 0 || e.which == 8))
            {
                return false;
            }           
        }
        
    });//obj.keypress(function(e){
    
}//soloNumeros

function validarEmail(valor) 
{
    var filter=/^[A-Za-z][A-Za-z0-9_]*@[A-Za-z0-9_]+.[A-Za-z0-9_.]+[A-za-z]$/;
    if (filter.test(valor))
      return true;
    else
     return false;
}//validarEmail()