SetInterval Not Calling Cursor Function

In my mouseClick function I have a setInterval which call cursor function. Unfortunately it's not working. Below is my code:

var canvas;
var ctx;
var cursor_width = 1;
var cursor_height = 16;
var wait_time = 500;
var repeat_time = 1000;
var height = 22;
var textbox = new Array();
var repeat; .....

I tried the following code as well but I received a message telling me it's not a function
repeat = setInterval("this.cursor()", repeat_time);