  We present narrowband H-alpha imaging data of a small survey of nearby
edge-on spiral galaxies, aiming at the detection of `extraplanar' diffuse
ionized gas (DIG). A few of our studied edge-on spirals show signs of disk-halo
interaction (DHI), where extended line emission far above the galactic plane of
these galaxies is detected. In some cases an extraplanar diffuse ionized gas
(eDIG) layer is discovered, e.g., NGC4634, NGC 3044, while other galaxies show
only filamentary features reaching into the halo (e.g., IC 2531) and some
galaxies show no sign of eDIG at all. The extraplanar distances of the DIG
layer in our narrowband H-alpha images reach values of z<= 2 kpc above the
galactic plane. The derived star formation rates (SFRs) from the H-alpha flux
of the studied galaxies range from 0.05-0.7 M_{sun}/yr, neglecting a correction
for internal absorption. The variation of the SFR values among our sample
galaxies reflects the diversity of star formation within this sample. A
diagnostic diagram is introduced, which allows to predict the existence of gas
halos in `quiescent' galaxies based on the ratio S_{60}/S_{100} versus L_{FIR}
/ D^2_{25} in this diagram. We compare the positions of the non--starburst
galaxies with starburst galaxies, since these galaxies populate distinct
positions in these diagrams.
