static public String run(String programStr)
 {
	 try {
		    WggSimPLParser parser = new WggSimPLParser(new java.io.ByteArrayInputStream(programStr.getBytes()));
		    parser.syntax_Analysis();
		    SimpleNode node = (SimpleNode) parser.getTreeRoot();
		    Expression program = null;
		    program= generateSynatx(node);
		    return program.measure(new Env()).toString();
		} 
		catch (SimPLException e2)
		{
			return e2.toString();//+" "+e2.msg;
		}
		catch (ParseException e1) {
			return "Syntax Error!";
		}
		catch(TokenMgrError e3)
		{
			return "Syntax Error!";
		}
 }