Diff between calling a shell script with ./ and . ./

Hi ALL

I have a shell script named setUP in which i am sourcing one variable like

source var_name="CLASSPATH".

When i call it as ./setUP, it does not set the var_name variable. But when i call it like . ./setUP then var_name is set up. What is the difference between this two calls?

Thanks in advance
Sas

A moderator will probably also tell you this - no double dipping. You asked this same question in the Unix for Dummies section.

Correct. No double posting, continued here, thread closed.