Help Required for VAT Compliances

Dear All,

I am a retailer for glass & aluminium. Generally i purchase the same and sell it in margin. but right i have purchase glass worth rs. 40000/- and providing my customer to fix it the same at their premises (fixing in window & doors etc) and charging labour charges (Job work) for the same worth rs. 16000/-. So i want to know the following:

1. whether i should raise single bill for sell of the goods and services provide by me?

2. Is there any default in vat compliances like WCT?

Kindly help me to get out from this issue.

Best Regards,

Harpreet