passing variables from one page to another

Hi Everybody, Please forgive the basic nature of this question--I have looked at the manual, but I found that much of it went over my head. I'm trying to create a second level of a website that displays course listings. The first level lists a bunch of courses. I'd like users to be able to click on the title of a course to go to a page that contains details about that course. From what I understand, I should do this by making the title of the course on the first page (courses.php) a link to the second page (courseinfo.php) with a query string attached--so that the link would look like <a href="courseinfo.php?CourseID=12">Accounting 101</a> What I'm having trouble doing is coding the second page. Here's what I've done. When I run this, I get a blank page in return...if anyone can help, I would greatly appreciate it. Thanks in advance. Matt <?php $db = @mysql_connect("host","user","pword"); mysql_select_db("dln", $db); if ( !$CourseID ) { print ("no course id included") exit; }; $query = "Select * from course, disc, instit, prof where course.CourseID = $CourseID and course.DiscID = disc.DiscID and course.InstitID = instit.InstitID and course.ProfID = prof.ProfID; $result = mysql_query ($query); echo "MySQL error number " . mysql_errno() . ": " . mysql_error(); print ("<table border=\"0\" cellpadding=\"5\" class=\"default\">\n"); print ("<tr bgcolor=\"#ff9900\"><th>$CourseID</th></tr><tr><td>$CourseTitle</td></tr></t able>"); ?>