if thats just a string do this :
string oldString = "Emad ";
string newString = oldString.Replace(" ", "");
and if its gridview then do this :
on gridview's OnRowDataBound event :
foreach (GridViewRow row in YourGridName.Rows)
{
Label lbl = (Label)row.FindControl("YourLabelNameWithWhichUWantToReplaceTheSpaces");
lbl.Text.Replace(" ", "");
// or
lbl.Text.Trim();
}