Looking for a way to have customer enter own dollar amount for item w/o having to enter item number....
Here are a couple suggestions:
OPTION 1) Perhaps you could use the "uShopInput3" applet .... with the id set to your gift certificate id and the price set to $1.00. Then just provide instructions on the HTML page to say "Enter the gift certificate amount in the quantity box." (And if you feel the "Qty" label is misleading... you could technically hide it entirely by setting the "text_color" parameter equal to the "background_color" parameter.)
OPTION 2) Perhaps you could use the "uShopInput17" applet ... and have the customer select the gift certificate amount from a pre-defined list of ammounts (shown in the menu). (You could hide the quantity box and the other fields in the menu.)