Submitted paper with wrong title I wrote a paper which got accepted in a reputed journal, I wrote another paper with completely different work, however when  I submitted the second paper I mistakenly (actually I was in a hurry) with the old title (of accepted paper). What should I do now, should I withdraw my paper, or let the editor know about this, the paper is still in phase of "waiting for editor assignment"
thankyou
Such errors are not uncommon. Just inform the journal through the editor in chief or wait until you actually have an editor. It is normally possible to change titles in any case up to the time of finalization. 

At worst there will be a bit of confusion until you make the correction.