vb.net - How to ignore if a cell is empty nothing -

how use roscolor() ignore value (like empty cell) ? color row if value upper 5 when there nothing in cell, want ignore roscolor() apply, how?

public sub roscolor()     integer = 0 quotedatagridview1.rows.count() - 1 step +1         dim val integer         val = quotedatagridview1.rows(i).cells(3).value         if val = vbempty              quotedatagridview1.rows(i).defaultcellstyle.backcolor = color.white          elseif val < 5             quotedatagridview1.rows(i).defaultcellstyle.backcolor = color.red         elseif val > 5 , val < 10             quotedatagridview1.rows(i).defaultcellstyle.backcolor = color.lightyellow           end if      next  end sub 

you can check empty value following

public sub roscolor()     integer = 0 quotedatagridview1.rows.count() - 1 step +1         dim val = quotedatagridview1.rows(i).cells(3).value         if isdbnull(val) or val nothing             quotedatagridview1.rows(i).defaultcellstyle.backcolor = color.white         elseif cint(val) < 5             quotedatagridview1.rows(i).defaultcellstyle.backcolor = color.red         elseif cint(val) > 5 , cint(val) < 10             quotedatagridview1.rows(i).defaultcellstyle.backcolor = color.lightyellow         end if