var submitcount=0;

function validate() {

if(document.Reservas.Nome.value.length <1)
{alert("You left the Name field blank.")
document.Reservas.Nome.focus();return false}

if(document.Reservas.Sobrenome.value.length <1)
{alert("You left the Last Name field blank.")
document.Reservas.Sobrenome.focus();return false}

if(document.Reservas.Telefone.value.length <8)
{alert("You must enter a Telephone number with area an country code.")
document.Reservas.Telefone.focus();return false}
	
if (document.Reservas.Email.value!="") 
{
if (document.Reservas.Email.value.indexOf("@")==-1 || document.Reservas.Email.value.indexOf(".")==-1 || document.Reservas.Email.value.indexOf(" ")!=-1 || document.Reservas.Email.value.length<6) 
{alert("Sorry, your e-mail address is not valid.");
document.Reservas.Email.focus();return false}
}
if(document.Reservas.Email.value.length <1)
{alert("You must enter a valid e-mail address")
document.Reservas.Email.focus();return false}

else 
   {
   if (submitcount == 0)
      {
      submitcount++;
      return true;
      }
   else 
      {
      alert("The Form has been submited already, Thanks!");
      return false;
      }
   }
}