Microsoft Windows [Version 6.1.7600]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.
C:\Users\x>cd desktop
C:\Users\x\Desktop>up1.pl


 Please ENTER Database Name (.txt): rc.txt

 rc.txt Database:

A:50:r1
B:45:r2
C:40:r3

 WELCOME to Students' Database:

 Enter the Registration Number to view the details: r1

 The details of the student are:

Can't call method "display" on an undefined value at C:\Users\x\Desktop
\up1.pl line 45, <STDIN> line 2.

C:\Users\x\Desktop>