when i am passing value to taxvat variable NULL i am getting syntax error and if i am paasing value to it, it working proper but my requirement is accept the null value as well
![enter image description here](https://i.sstatic.net/fdsbbi6t.png)
when i am checking the log i am getting this kind of error
![enter image description here](https://i.sstatic.net/tC1Hl95y.png)
any help will be appreciate