Drop Down Functions for a Common Browser Menu

The next statement is an if-statement with a number of statements inside. The condition of the if-statement tests to see if the SPAN element exists before its block is executed. It is possible that some cells may be empty and would not have any SPAN element, though we do not have any in our example.

We have developed the ID of a possible existing SPAN element based on the iteration and position number. That is why the condition has to test whether the SPAN element exists before it is displayed. This is a precaution, because we do not know whether if we try to display a SPAN element that does not exist, the software would go into an error state.

We already have the ID of the table cell, and the ID of the SPAN element in the cell at the particular iteration. The background color of the table cell, whose SPAN element is displayed, has to be set to brown as a result. When the background of the cell is colored, the cell becomes opaque, and you cannot see through it. The first line inside the if-block gives a brown color to the background of the cell that has the SPAN element to be displayed. The next line displays the SPAN element, by giving the "block" value to its display property.

The next statement gives the content of "true" to the corresponding cell in Boolean Table. The statement that follows creates the number part of the SPAN element ID that will be written into the corresponding cell in the Number Table.

The last statement writes this number into the corresponding cell. You may ask, why not write the ID? As we go along you will see that we need the number more than the ID (which is the number preceded by S).