DetailsView Separator Image Between Two Rows?

I'm trying to use DetailsView of asp.net to display data in the following format:

Name: Adam
Age: 18
Gender: M

And I wanted to add a lines (gray image) between each two rows

Name: Adam
Age: 18
Gender: M

I managed to put the image as another row between each two rows, but it make it start only on the second column (of the data) because the first column "saved" for the header (which is empty)

anyone knows how can put the image between the rows and make it "use" the whole line?

I did what I did using:

<asp:TemplateField>
<ItemTemplate>
<img src="../Images/thin_grey_separator.png" alt=""/>
</ItemTemplate>
</asp:TemplateField>