Add an extra column before an answer option column in single grid question

Challenge

In order to have extra space between an answer option column and others in single grid question

As a questionnaire creator

I want to add an extra empty column before a specific answer option column

Example

I have a single grid question like below.

I want to separate Don't know column from others.
 

Solution

Search for the cell containing Don't know - answer option text, and add a cell right before that cell with rowspan equal to the number of rows in the grid.

Code

 1 quest.addEmptyColumnBefore = function(answerOptionValue, cssClass)
 2 {
 3     //get the number of rows
 4     var n = $(".grid_inner")[0].rows.length;
 5    
 6     $("#grid_answeroption_text_" + answerOptionValue)
 7         .before(
 8             $("<td rowspan=\""+(n + 1)+"\">&nbsp;</td>")
 9             .addClass("grid_answeroption_text")
10             .addClass(cssClass)
11         );
12 }
13 quest.onInit = function()
14 {
15 	var dontKnow_value = 3;
16 		
17 	this.addEmptyColumnBefore(dontKnow_value, "grid_space_cell");	
18 }