C# datagridview help >_

[C# Programming]

Hi All,

my program requires the user to open a specific text document with fixed values inside and clicking plot will plot the values from the text document onto the pictureBox. I need help in where if the user didn't open the text document and clicked the plot button, an error message will show from the MessageBox and requires the user to locate and open the text document. Any help will be appreciated!

Thanks http://www.barakasoft.com/script/Forums/Images/smiley_smile.gif

P.S I'm new so i'm not sure how to attach a picture so i used tinypic link http://i41.tinypic.com/2elgjur.png)