Web Forms :: Employee Portfolio - Image Size Crop

I am building the employee portfolio where each employee enters his/her data. at this stage am I building the image crop where an employee uploads image and then crops it. I am getting this error: Input string was not in a correct format.

Here is the code: 

 namespace Testing {
public partial class Wizard : System.Web.UI.Page {
String path = HttpContext.Current.Request.PhysicalApplicationPath + "images";
protected void Page_Load(object sender, EventArgs e) {
}

[Code] ......