your syntax on the while loop is still incorrect.

You have:

while ($string_tested); {
statement
statement
statement
}
[download]

It should read like this:

while (test)  {

statement0;
statement1;
statement2;

}
[download]

I echo the approach suggested by mzedeler and also that you have a look at the tutorials section. Oh and always  use strict; use warnings;.