help: Problem with cgi form

[netvegetable]

I'm a beginner. How do I do this? It's probly very simple ......

I have a hidden input on a cgi form... 

    print '<INPUT TYPE=HIDDEN NAME= "last_pos" VALUE=',last_byte_pos,'>'

I need the VALUE to be the  variable "last_byte_pos", but unfortunately 
when I run the script for the first time the script crashes because it's 
undeclared. 

What subroutine do I use to check if last_byte_pos is undeclared, and 
assign it a default value if it is? 



-- 
"You can tell whether a man is clever by his answers. You can tell whether 
a man is wise by his questions."  Naguib Mahfouz

netvegetable at dingoblue.net.au