Multiple tasks for form control

I have two Textboxes and 2 button on my webform.one text box is QuotationNumber(autogenerate) and another textbox is Revision(autogenerate).I have two buttons AddQuote and AddRevision.I need following tasks
1.When i click AddQuote button QuoteNumber automatically generated.
2.when i click AddRevision button all the existing QuoteNumbers should be listed in dropdown and Revision Textbox should be autogenerated.QuoteNumber shouldnot be autogenerated QuoteNumber column should become dropdown with all existing quotenumbers from the database.
 
 
 
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