I am unable to generate a reference number for the TDS amount deducted. How can I add a reference number?

If you are unable to generate a reference number for TDS amount deducted Then you have to 
 follow the steps 
 Step1 go to administration menu and click on configuration then click on feature options 
 Step2 click on TDS TCS option and check that Skip tds reference option must be disable 
 and warning for tds on purchase option enable as warning only 
 Step3 the party master must have enabled the tds on expense and tds on payment or purchase 
 and payee category must be tagged 
 Step4 in expense ledger also need to enable tds on expense and tds category 
 Step5 the tds bill sundry ledger must have disable the adjust in purchase amount and account head to post should be tagged under TDS ledger and tds ledger group should be duties 
 and taxes and tax type TDS non salary or salary
 Step6 then on purchase voucher while limit exceed tds generation message will show in voucher make it yes then the reference box will open where you need to fill R for sale and E for scrap 
 Step7 on payment voucher while you enter the expense ledger tds box will open their you 
 need to apply tds then the value will calculate and at the time of saving voucher Reference box 
 will be open