how to add map layer overlays in openlayers?

Question

i have 3 shapefile ready in a map file, and rendering it on mapserver. what i need is to and these layer overlay one over the other.how can i do this

Answer 1

Would this help?

for your question in the comment,

General openlayers examples You'll also find Geoext useful.

In the examples, you can see the different ways to add a layer to open layers

Answer 2

When you define a map in openlayers you should define one or more BaseLayer(but just one of them is displayed at a time). Upon these layer you could load as many overlay as you prefer.

Have a look here for the definition of overlay in OpenLayers.

This is an example of overlay with OpenLayers.

Anyway you could find a lot of samples just googling..