{"c2array":true,"size":[7,1,1],"data":[["2","test"],["3","Oscar"],["4","Oscar"],["5","test"],["6","test"],["7","oscar"],["8","Oscar"]]}
[/code:3jkdgoc4]
Thanks in advance!

$result=mysqli_query($con, $sql);

		$emparray = array();
		// Start looping rows in mysql database.
		while($rows=mysqli_fetch_assoc($result)){
			$emparray[] = $rows;
		// close while loop 
		}
		//print_r($emparray);
		//echo json_encode($emparray);
		$output = array(
	   'c2array' => true,
	   'size' => array(
	       0 => count($emparray),
	       1 => 1,
	       2 => 1
	   ),
	   'data' => array()
	    );

	    $x = 0;
	    foreach ($emparray as $value) {
	   $output['data'][$x] = array();
	   $output['data'][$x][0] = array();
	   $output['data'][$x][0][0] = $value["nombre"];
	   $x++;
	    }

	    echo json_encode($output);
[/code:2vqhamr3]

Now the array data is correct in the debug layout.
[code:2vqhamr3]{"c2array":true,"size":[7,1,1],"data":[[["test"]],[["Oscar"]],[["Oscar"]],[["test"]],[["test"]],[["oscar"]],[["Oscar"]]]}[/code:2vqhamr3]
But the combobox is showing infinite options. lol

---UPDATE----

I did it! 
I fix the combobox like this:
[img="http://s13.postimg.org/is1qrumdz/Sin_t_tulo.png"]
OK now, how can i add an id in the same JSON? i mean i want to get the id of the users from the database, i guess i need them in the JSON query so i have to modify the SQL query to show it on the JSON but i dont know in what format.

Now my JSON looks like this:

[code:2vqhamr3]{"c2array":true,"size":[7,1,1],"data":[["2","test"],["3","Oscar"],["4","Oscar"],["5","test"],["6","test"],["7","oscar"],["8","Oscar"]]}[/code:2vqhamr3]

The number are the id´s of each name in the db, but the c2 array shows only the id of each element but no the name, i want to show the name in the combobox but use the id to work with the mysql db.

$emparray = array();
		// Start looping rows in mysql database.
		while($rows=mysqli_fetch_assoc($result)){
			$emparray[] = $rows;
		// close while loop 
		}
		echo json_encode($emparray);
[/code:wvakingv]
what do i have to add to get that format?

Thanks in advance!

[{"nombre":"test"},{"nombre":"Oscar"},{"nombre":"Oscar"},{"nombre":"test"},{"nombre":"test"},{"nombre":"oscar"},{"nombre":"Oscar"}][/code:z9g7g4el]and the code:
[img="http://s12.postimg.org/xdfzouu7x/Sin_t_tulo.png"]
can you help me plz?

Thanks in advance.