going from one loop to another, newbie here. 1

I'm taking qbasic in school and we have to write a pice of software that manages an auction. Pretty much we're free to be creative and do what we want as long as the software works and you could be a complete idiot and not screw the program up. Right now it starts out fine, but has trouble in the middle. I have it ask for the name of the item, the starting price, the first bid which i made a do until loop so that the first bid has to be greater than the starting price, that works all fine....but then i want it to go to 'next bid' and only accept bids that are higher than the previous high bid. It jumps immediatly from after you enter a valid number for the 'first bid' to what i want it to do at the end....say the high bid, ask for the high-bidders name, and then say '(name) has won the (item)'

here is the code i have so far, if you can tell me what i'm doing wrong i would appreciate it bigtime. I want to get one step ahead in the class, and if i could bring in a stable and pretty reliable program on monday i would be happy.

CLS

PRINT "**AUCTION**"
PRINT " "
PRINT "To stop auction, enter 0"
PRINT " "
PRINT "Enter name of item "
INPUT item$
PRINT " "
PRINT "Enter starting price: "
INPUT minn

DO UNTIL low > minn
PRINT "Enter first bid: "
INPUT low
LOOP


DO UNTIL bid = 0
PRINT "Enter next bid"
INPUT bid
IF bid > min THEN bid = min
IF bid < min THEN bid = invalid
IF bid > min THEN bid = max
LOOP


PRINT &quot;AUCTION ENDED&quot;
PRINT &quot; &quot;
PRINT &quot;High bid: &quot;; max
PRINT &quot;Enter name of high bidder: &quot;
INPUT name$
PRINT name$; &quot; has won the &quot;; item$
END