Embbed Javascript on Java6 code, this code as a calculator on the first parameter

Eval.java

import javax.script.*;

class Eval {
  static ScriptEngineManager manager = new ScriptEngineManager();
  static ScriptEngine engine= manager.getEngineByName("js");

  public static void main(String args[])  {
	System.out.println(calc(args[0]));
  }
  public static String calc(String line) {
 	try { 
		engine.eval("i="+line); // calculate expression
		return(engine.get("i").toString()); 
	} 
	catch(ScriptException se) {return("ERROR"); }
  }
}