function validation(form) {
      
      
if(form.first_name.value == '') {

alert('Please enter your first name.');
form.first_name.focus();
return false;
}


if(form.last_name.value == '') {

alert('Please enter your last name.');
form.last_name.focus();
return false;
}

if(form.email.value == '') {

alert('Please enter your email address.');
form.email.focus();
return false;
}

if(validateEmail(form.email , "Please enter a valid email address." ) == false)
{
  return false;	
}


if(form.company.value == '') {

alert('Please enter your company.');
form.company.focus();
return false;
}




return true;
}

function validateEmail ( emailField, errorMsg ) {
 emailpat = /^([a-zA-Z0-9])+([\.a-zA-Z0-9_-])*@([a-zA-Z0-9])+(\.[a-zA-Z0-9_-]+)+$/;
 if( !emailpat.test( emailField.value ) ) {
  alert( errorMsg);
  emailField.focus();
  emailField.select();
  return false;
 }
 return true;
}