function checkform(form)
{
  if (form.name.value == "")
  {
  alert( "Please enter your name." );
  form.name.focus();
  return false;
  }

  function echeck(str)
  {
  var at="@"
  var dot="."
  var lat=str.indexOf(at)
  var lstr=str.length
  var ldot=str.indexOf(dot)

  if (str.indexOf(at)==-1)
  {
  alert("Invalid email address")
  return false;
  }

  if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr)
  {
  alert("Invalid email address")
  return false;
  }

  if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr)
  {
  alert("Invalid email address")
  return false;
  }

  if (str.indexOf(at,(lat+1))!=-1)
  {
  alert("Invalid email address")
  return false;
  }

  if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot)
  {
  alert("Invalid email address")
  return false;
  }

  if (str.indexOf(dot,(lat+2))==-1)
  {
  alert("Invalid email address")
  return false;
  }

  if (str.indexOf(" ")!=-1)
  {
  alert("Invalid email address")
  return false;
  }

  return true;
  }

  var email=document.contact_leonardo_canziani.email

  if (echeck(email.value)==false)
  {
  form.email.focus();
  return false;
  }
  
  if (form.message.value == "")
  {
  alert( "Please enter your queries, comments or suggestions." );
  form.message.focus();
  return false;
  }

  return true ;
}