Twitter button not working in Random Quote Machine

I am working on Random Quote Machine and the twitter button that i have made is not working. I have given link also but i dont know whats the problem.
This is the code:-

I agree with @SkyC
But if you want a direct answer for why it isnt working as you have it now"");

you need to remove the equal sign"");

and it will only go after you click next quote at least once.

thanks @SkyC and @JashuHB…the problem is solved.