Javascript for the Cab Calculator: Explained

The HEAD Section Explained
I declared the function "cabs".
Cabs is defined by an if statement. If i, which is my counting variable, minus one (since I initialized at one I end up with one more than I need), is greater than 1, the computer prints "cabs" to the screen.

The BODY Section Explained
I start out by prompting the user for how many people they need to transport, that value is stored in the variable j.
Then I defined a new variable, k. K is equal to j/4 (since by law you're supposed to have at most four passengers in a cab), which is the number of cabs required, rounded to the next whole number (by the Math.ceil, built in function).
If k (the number of cabs) is less than twenty, the loop starts. The loop counts from one to k, incrementing by one each time. Every time the loop runs it prints a picture of a cab.
After the loop ends it writes "You need," and calls the function "cabs" (explained above)
If k (the number of cabs needed) is greater than 20, it prints the statement, "Maybe you should hire some limos."