add:  var taskid = birtUtility.getTaskId( ); if( taskid.length > 0 ) {  this.__l_show_cancel_button( );   var oCancel = this.__loc_cancel_button( ); if( oCancel ) oCancel.disabled = false; } else {  this.__l_hide_cancel_button( ); }  
context: 	__start : function( )	{		this.__timer = window.setTimeout( this.__cb_bind_closure, this.__interval );	},
meta: 855	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/855/f5d3573e55ae98083c793f6d1503a85bbee5507a/BirtProgressBar.js/clean/viewer/org.eclipse.birt.report.viewer/birt/webcontent/birt/ajax/ui/app/BirtProgressBar.js