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.form.email

if ((email.value==null)||(email.value=="")){
alert("Please enter your email address")
return false ;
}

if (echeck(email.value)==false){
form.email.focus();
return false ;
}

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

return true;
}