Adapt script to ea for making screenshots every 15 min (adaptable)

Hello, 

I have a script to make screenshots. Now I want to run it every 15 minutes(adatable number) So it needs be an EA instead of a script. So basiscally the script should be converted to ea thats runs every 15 min. The name of the files should be stay the same as it is in script now also the resolution should not be different. Also the location were the files are store should not be different. 

Below the script. 

void OnStart()
{
   //--
   // if(TimeCurrent() >= D'2018.12.15'){
   //    MessageBox("Testing Period is finished!");
   //    return ;
   // }
   //--
   long chartId = ChartFirst();
   while(chartId != -1)
   {
      string fileName = ChartSymbol(chartId) + "-M" + string(ChartPeriod(chartId))  + ".png" ;
      int width  = 1871;(int) ChartGetInteger(chartId, CHART_WIDTH_IN_PIXELS);
      int height = 871;(int) ChartGetInteger(chartId, CHART_HEIGHT_IN_PIXELS);
        ChartScreenShot( chartId, fileName, width, height );
  
 
      //--
      chartId = ChartNext(chartId);
   }
}
//+------------------------------------------------------------------+