Thankyou for your time Olie, I do understand the basics of classes, but
obviously still have much to learn! I had thought that the load
function did not exit until after the closing brace, and because i
called the fileopen function before this i had beleived that the
variable would still be accesible. I have moved the string outside of
the load method and into the class and it is now working.

One thing I can't understand is why if i leave the string variable in
the load function and add 'public' in front of it, like so: public
string file  - why i can't then access it in the function openfile. I
had thought that public meant that anything in the code file can access
the variable?
-----------
also here is the rest of the class, in case it helps anyone looking at
my opendialog problem.

namespace MyNewProject{
   partial class Form1
   {
       /// <summary>
       /// Required designer variable.
       /// </summary>
       private System.ComponentModel.IContainer components = null;

       /// <summary>
       /// Clean up any resources being used.
       /// </summary>
       /// <param name="disposing">true if managed resources should be
disposed; otherwise, false.</param>
       protected override void Dispose(bool disposing)
       {
           if (disposing && (components != null))
           {
               components.Dispose();
           }
           base.Dispose(disposing);
       }

       #region Windows Form Designer generated code

       /// <summary>
       /// Required method for Designer support - do not modify
       /// the contents of this method with the code editor.
       /// </summary>
       private void InitializeComponent()
       {
           this.openFileDialog1 = new
System.Windows.Forms.OpenFileDialog();
           this.SuspendLayout();
           //
           // openFileDialog1
           //
           this.openFileDialog1.FileName = "openFileDialog1";
           //
           // Form1
           //
           this.ClientSize = new System.Drawing.Size(292, 266);
           this.Name = "Form1";
           this.Load += new System.EventHandler(this.Form1_Load);
           this.ResumeLayout(false);

       }

       #endregion

       private System.Windows.Forms.OpenFileDialog openFileDialog1;
   }
}

Thankyou that seems to be working much better, i have the following: -

   public partial class Form1 : Form
   {
       private void Form1_Load(object sender, EventArgs e)
       {
           string file;
           file = FileOpen();
       }

       private string FileOpen()
       {
           string file = null;

           if (openFileDialog1.ShowDialog() == DialogResult.OK)
           {
               file = openFileDialog1.FileName;
           }

           return file;
       }
   }
}

----
but the open file dialog isn't being displayed when my form is run.

I found out i had named it wrongly (wrong case which is why it wasn't
displaying).

can someone suggest why the open dialog isn't being displayed please?

thankyou