How do I create an auto bidding feature in webid?

It will require the bidder to set their maximum bidding price, so that the system will automatically place the bids at regular intervals whenever there is a new bid, until the maximum is reached.

What do I have to do to achieve this?

Thanks in advance.

What i can suggest here is that it can be done through triggers.

When a bid is made,it means that an update is made in certain table or an insert for the first bid,
so on update/insert in that particular table fire one trigger.

This trigger will check that is that particular item is existed in the automatic bidding list table.
Automatic bidding list table will contain the item detail,user detail,timing and price details of the users who has opted for automative bidding for a particular time limit.

So now the scenerio would be like this,
On insert/update of a particular bid on an item Trigger will be called
This trigger will check if the item on which a bid is made exists in the automatic bidding list table
If it exists,then get the user detail and maximum price of the user that he/she is wishing to bid

Now the trigger will contain whether the current bid price is less than the maximum price limit,if yes then it will bid a bit higher,it means it will insert a bid.

If current bid is more than maximum price,then the bid for that particular will be close.

I hope that it will help you. :)
Good luck....