A blank line("\n\n") is required to signal the end of your headers.

print "Content-type:text/html\n\n"; should fix the issue in this script. When you get into more complicated CGIs dealing with cookies, expirations and such, you only put the blank line at the end of all headers.

print "header1:value1\n";
print "header2:value2\n";
print "header3:value3\n\n";
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You may also want to consider using CGI methods to output you headers and html. I personally prefer HTML::Template, but either will work.