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Cascading drop box holds old value if empty on auto post back

Posted By:      Posted Date: September 03, 2010    Points: 0   Category :ASP.Net
I have 3 drop boxes: 1.) Choose Operation 2.) Choose Site 3.) Choose Area. All three of them are linked to an SQL server database which has 3 tables following the same heiarchy of order. I.e. Areas belong to a Site and Sites belong to an operation. And there can only be one operation per site, or one site per area. First you select an operation, then the page auto postbacks to filter the sites. Then you pick a site and again it autopostbacks to filter the areas. The issue I am having is that when an associated operation has no sites underneight it, and therefore no areas under that, the previous values that were in the boxes are displayed and the user can't click on the boxes anymore. I think this is kind of cheap looking and would like a way to make it so the boxes are clear (i.e. nothin in them). Is there anyway to check if they are going to freeze like that and assign them blank values??Any suggestions on this issue would be greatly appreciated!-Jordan

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