Withholding tax calculation with formula base problem

Question

Dear all,
I maintained some formula depend on client requirement. for example:
up to 200,000.00  no withholding tax                                                     
2 lax to500,000.00  <1.00 %> tax                                                   
5 lax to 1,500,000.00 <2.50%> tax 1.00 % Reduce on 500,000.00 base amount                    
15 lax to 2,500,000.00 < 3.50 % > tax 2.50 % Reduce on 1,500,000.00 base amount                         
25 lax to 3,000,000.00 < 4.00 % > tax 3.50 % Reduce on 2,500,000.00 base amount                         
30 lax to 99,999,999,999.00     <5.00 %> tax 4.00 % Reduce on 3,000,000.00 base amount          
Like this i maintained slabs in formulas for calculating withholding tax. depend on this formula up to 2 lax their is no tax. after crossing 2 lax up to 5 lax 1% tax
in this case tax will calculate based on total vendor invoices. But hear it is calculated on present invoice based only. for example i posted 2 invoices with amount 2 lax. it means i reached 1st slab up to 2 lax no Tax. system also calculated like that only. but when i try to post another invoice with amount 3 lax system is calculated 1% tax on 3 lax amount only. but already i posted 2 lax invoice in vendor account. system not considered this amount.
*but actually in this case i want to calculate 3+2= 5 lax * 1% tax . but hear my system is not consider previous invoices .*
Please do need full help.....
Regards,
Krishna Valeti
Edited by: chaituvaleti on Sep 9, 2011 8:51 AM
Edited by: chaituvaleti on Sep 9, 2011 8:54 AM
Edited by: chaituvaleti on Sep 9, 2011 9:02 AM

Answer 1

Can you please share the information to us,  it will be a great information to us , thanks in advance.........