Dear @rahul7250, that is - by the rules of steemit - not the way delegation works, I'm afraid. If you want to add some SP you have to delegate the new sum of both: old SP plus new SP. Now you have delegated only 37 SP to me.
In 7 days, the difference between the old and the new delegation will be back under your control. Until then, your delegation to me is only 37 SP…
I'm very sorry to say so. Please understand, that this is not my rule and I can do nothing about that :(