Multiple counters in Javascript for loop

You've got some semicolons where you want commas:

for (i=1, j=0, k=150; i<=5; i++, j+=30, k-=30) { /* do work */ }

You should only have three "statements" inside your for

for( [init]; [test]; [increments]) { [block] }

To do multiple [inits] or [increments] you have to use the sometimes magical, but oft forgotten, comma operator

too much semicolons there

for (i=1; j=0; k=150; i<=5; i++; j+=30; k-=30){

should be

for (i=1, j=0, k=150; i<=5; i++, j+=30, k-=30){

You made gramatical errors in your code that you could have easily spotted had you used static code analysis tools such as the lovely JSHint.

In addition, you should further understand the use of the comma operator in JavaScript, our site has a few answers on it already.