function banner(campo)
{	
    if(campo.nome_form.value =="")
		{
		alert("Campo nome obrigatório");
		campo.nome_form.focus();
	    document.getElementById("nome_form").style.border = "1px dotted #f00";		
		return false;
		}
	else	
	
	
	if (campo.email_form.value =="")
	    { 
	    alert("Campo email obrigarório");
	    campo.email_form.focus();
	    document.getElementById("email_form").style.border = "1px dotted #f00";
	    return false;
	    }	

	else
	
	valido = /^[a-zA-Z0-9][a-zA-Z0-9\._-]+@([a-zA-Z0-9\._-]+\.)[a-zA-Z-0-9]{2}/;
	var email = campo.email_form.value; 
	if (!valido.exec(email))
		{
	    alert ("Coloque um email valido");
	    campo.email_form.focus();
	    document.getElementById("email_form").style.border = "1px dotted #f00"; 
        return false;
	 	}
	
	else
		
	if (campo.ddd_form.value =="")
	    { 
		alert("Campo DDD brigarório");
		campo.ddd_form.focus();
		document.getElementById("ddd_form").style.border = "1px dotted #FF0000";			
		return false;
		}	
    else	
	
    if (campo.tel_form.value =="")
	    { 
		alert("Campo telefone obrigarório");
		campo.tel_form.focus();
		document.getElementById("tel_form").style.border = "1px dotted #FF0000";			
		return false;
		}	
    else
	
	campo.submit();
}