Where the script lacks steam (Mere Hamdam Mere Dost)

I had seen Mere Hamdam Mere Dost a long, long time ago. So, I didn't quite remember much from this Amar Kumar film except for the title track and the scintillating club song, Humko to ho gaya hain pyar , picturised on the dazzling Mumtaz. In fact, I vividly remember the song Na jaa kahin ab na jaa, simply because of the long refrains in the voice of Mohd Rafi, the oh-so handsome Dharmendra in a