Javed Akhtar added a couple of stanzas to "khaike paan banaaraswaalaa" for Don (2006)
which was written by Anjaan for the original Don (1978)
Interestingly, in one of the stanzas of the 2006 song Shah Rukh says "wo nain dwaar se man meN aake tan mein jwaalaa jagaatii hai" which is strikingly similar to a song written by Prem Dhawan for the 1959 film Sawan. The mukhRaa of the song is
"nain dwaar se man meN vo aake tan meN aag lagaa_e"