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# Control source

 P: 7 hey i am having difficulties basically i have 4 frilds named: 1)sub total-( this is the total not including the vat) 2) VAT-( this is wther the vat is 0.00 or 0.175) 0.175 being the vat rate we use in the UK.. for this feild i created a drop down list which consisters of : 0.00 0.175 3) VAT (T1)- Vat (t1) is the sum of sub total * VAT 4) Total including VAT- (this is the sum of sub total + VAT(T1) ok in the control source for VAT T1 i entered the following as my formula : =[sub total] * [Vat] for my total including vat feild i entered this formula: =[sub total] + [VAT (T1)] now in my forms these formulas seem too be working perfectly fine however wen i go bak to my table ... both VAT (T1) and TOTAL INCLUDING VAT come up as 0.00 :S:S maybe i am writing the formula wrong? also for the feild VAT it is a drop down box so am not sure .. if this changes anything please could anyone kindly get bak to me as i am indeed struglling regards Noor Aug 4 '08 #1
4 Replies

 Expert 2.5K+ P: 3,532 First off, it is seldom necessary or advisable to store calculated values in a table. This wastes disk space and increases work time; a retrieval from disk will almost always take longer than a calculation done on the fly, and this is certainly true in this case. You simply re-calculate when needed. You can either do this in a form as you've done here, or in a report or underlying query. So you should delete the field from your table, and from your query, if you're using one as the record source for your form. But you do need to have the VAT value stored! Otherwise, you won't be able to do the re-calculation mentioned above. In Design View for your form, you need to select the VAT combobox by clicking on it, then got Properties - Data and click in the Control Source box, then select the name of the field in your table that you want to hold the VAT. Now you should find that the VAT will be stored. Welcome to Bytes! Linq ;0)> Aug 4 '08 #2

 P: 7 hey thnks for ur reply.. is it posible u cud send me a data base sample bcz i honestly didnt get wat u werr saying lol sorry am fairly new to access please be patient with me regards Noor Aug 4 '08 #3

 Expert 2.5K+ P: 3,532 I'm sorry, if the simple instructions I've given you are beyond your comprehension, sending you a sample database won't be of any use to you either! You'd still have to do the same things I've already told you! And in the future, please refrain from using "texting" abbreviations in your post. It's annoying and is not considered acceptable behavior here. Linq ;0)> Aug 4 '08 #4

 Expert Mod 2.5K+ P: 2,545 Hi Noor. This site is staffed by volunteers who willingly try their best to assist others with Access issues, but we cannot do the work for you - you have to be able and willing to experiment and try out the advice you are given. It is not acceptable to request sample databases for simple requests - particularly when you clearly have not implemented the advice on much the same topic given in response to your first post linked here. Linq is right to call time on your request here, and to point out that the use of textspeak is not acceptable on this site. For many readers for whom english is not their first language such abbreviations are impossible to read - please do not use them here. -Stewart Aug 4 '08 #5