Solution to HP Officejet 6500 Ink Problem

Does your product look like this?

I am sure this is a common problem to all of those who use this product (i googled it and saw that a lot of users have post about this). Many have given their solutions but none of them work on me till i decided to sit down and think on my own.
The black cartridge and one of the colored cartridge failed to print. and this is not that the ink level is down/ out of ink. My printer stayed idle for long time and i can say that it's clotting problem.
Anyway, this is how you solve it;
1.  Go to setup on the printer
2. Tools
3. click till you find cleaning printhead
Then wait for it while it is cleaning the printhead. this might take several minutes.
4. After it finishes it will print level one
If it hasn't print all the colors. continue with level two cleaning (it will ask you if you should continue).
Level two won't fail you ;)