IF Statement Problem

[jabel]

I am trying to write an IF statement in cell I6:
cell H6 contains a time, Cell H4 contains the fastest time. I want I6 to display 1D if HG is between H4 and 0.499, 2D if HG is between H4 and 0.998, 3D if H6 is between H4 and 1.498 and 4D if H6 is between H4 and 1.998
Here is my formula:
=IF(H6<=$H$4+0.499,"1D"),IF(H6<=$H$4+0.998,"2D"),IF(H6<=$H$4+1.498,"3D"),IF(H6>=$H$4+1.998,"4D")

I keep getting the #VALUE! error

 

[VoG]

Perhaps

=IF(H6<=$H$4+0.499,"1D",IF(H6<=$H$4+0.998,"2D",IF(H6<=$H$4+1.498,"3D",IF(H6>=$H$4+1.998,"4D"))))

 

[jabel]

Thank you!