C# - Prevent Empty Gridview Data From Populating " " Into Textbox?

I have this code that populates a textbox based on a cell in the selected row of a gridview

protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
{
txtComment.Text = row.Cells[14].Text.Trim();
}

It displays in the txtComment textbox if Cell[14] has no data. Is there a way to prevent the from appearing when there is no data in the cell of the selected row?

Edit
I tried this and it didn't work

if (row.Cells[14].Text.Trim().Length > 1)
{
txtComment.Text = row.Cells[14].Text.Trim();
}
else
{
txtComment.Text = row.Cells[14].Text = "";
}

This worked

if (row.Cells[14].Text.Trim()!=" ")
{
txtComment.Text = row.Cells[14].Text.Trim();
}
else
{
txtComment.Text = row.Cells[14].Text = "";
}