Customer can't create new account

[ramsharan]

I am using oscommerce for my shopping site.When customer tries to create their account,even when the supplied email address is valid it says that it's invlaid email address and once the continue button is pressed this error message also comes on the top of the page:::

 

Warning: eregi(): REG_EMPTY in /public_html/handicraftpalace/includes/functions/validations.php on line 97

can anybody help me out on this please.I just don't know what's going on wrong?

I thought it was working few weeks ago.

 

thanks