function showTab(pid)
{
  var id = pid.substr(1,2);
  var i=1;
  for(i=1; i<=9; i++)
  {
    if(id == i){
      //alert(i);
      document.getElementById('t'+i).style.display = 'block';
      document.getElementById('tab'+i).className = 'chosen';
    } else {
      if(document.getElementById('t'+i)!=null && document.getElementById('t'+i).style.display == 'block'){
        document.getElementById('t'+i).style.display = 'none';
        document.getElementById('tab'+i).className = '';
      }
    }
  }
}

function validateContactForm(thisform){
  var proceed = true;
	with(thisform){

    if(email.value==null || email.value==""){ document.getElementById('email_1').style.display='block'; proceed = false; }
		else {
      document.getElementById('email_1').style.display='none';
      a_pozycja = email.value.indexOf("@");
      dot_pozycja = email.value.lastIndexOf(".");
      if(a_pozycja<1 || dot_pozycja-a_pozycja<2){ document.getElementById('email_2').style.display='block'; proceed = false; }
			else{ document.getElementById('email_2').style.display='none'; }
    }
	}
  return proceed;
}