donet invoke js

  var jsContext = new IronJS.Hosting.CSharp.Context();
  jsContext.ExecuteFile("myDlr.js");
  var fun = jsContext.GetFunctionAs<Func<double, double, double>>("cacl");
  double a = Double.Parse(this.tbxA.Text);
  double b = Double.Parse(this.tbxB.Text);
  var result = fun.Invoke(a,b);
  this.tbxResult.Text = result.ToString();

myDlr.js

var cacl = function (a, b) {
    return a*b;
};