First plugin trying to make

I am trying to make a plug-in that will keep track of employee access rights in our system. Right now I have buttons that will ask if they want to add new, view or modify an employee that they have working for them. That works but when I try and find out who is the user loged in I just get a white page. PHP syntax is correct and problem is when I put in the code:

get_currentuserinfo();

Here is the page that I am talking about.

<?php global $current_user;
      get_currentuserinfo();
	  $fname=$current_user->user_firstname;
	  $lname=$current_user->user_lastname;
$new=$_POST["New"];
$view=$_POST["View"];
$modify=$_POST["Modify"];

if ($new =="New")
	{
	echo "1";
	}

if ($view =="View")
	{
	echo "2";
	}

if ($modify =="Modify")
	{
	echo "3";
	}

echo $fname." ".$lname." Thank you for being loged in.";
?>

The plug-ins that I have installed that I think might cause an error with it is the user access manager but I am not sure.