def to_js(element_id)
      js =  ""
      js << "\n<script type='text/javascript'>"
      js << load_js(element_id)
      js << draw_js(element_id)
      js << "\n</script>"
      js
    end
Generates JavaScript and renders the Google Chart in the final HTML output.

Parameters:
*div_id            [Required] The ID of the DIV element that the Google Chart should be rendered in.