<li>You <b>must</b> call the invoice_lines() function at least once - pass it a number of lines, and it returns a list of array references, each of two elements: a service description column, and a price column.
<li>In addition, the following variables are available:
<ul>
<li>You <b>must</b> call the invoice_lines() function at least once - pass it a number of lines, and it returns a list of array references, each of two elements: a service description column, and a price column.
<li>In addition, the following variables are available:
<ul>