add new cloumn to exsit dataset

Question

hi every body 

i have folder in my website where i can loop in it and get all files ordered i need to add anew column to an exist  data set  this my code 

 

string sourceDir = Server.MapPath("~/folder1/folder2/");

string[] fileEntries = Directory.GetFiles(sourceDir).OrderBy(filename => filename).ToArray();

foreach (string fileName in fileEntries)

{

string x = "<img src=\"" + Path.GetFileName(fileName) + "\" /><br />";

}

 

 this data set already have data i need to add anew colum to the same dataset with the image path from previous code

if (ds.Tables.Count > 0)

{

       // do something 

}

 

how it can be done