Hello, I am trying to make shure the amount is positive and is a float. (format: $$$.$$) if( $amount == "" && !is_float( $amount ) && !eregi( "^[_a-z]", $amount ) ){ print "Error"; } this code does not work when I the input is -25.00 What could be wrong? py p.s. I read what I could on regular expression, but obviously still learning...