ArrayList or Object assignment?

[NOMADMAN]

I have class edge:

public class GraphMap
{
    private ArrayList _vertices;

// ... deleted most of class, only important stuff...

    public void addEdge( int start, int end, double dist )
    {
        Vertex tempVert = new Vertex();
        tempVert = _vertices.get( start );
    }

This gives me the compiler error:
Incompatible type for =. Can't convert Object to Vertex.
tempVert = _vertices.get( start );

Why is this happening and can I get around it? Does using ArrayLists limit me to added classes that inherit Object class? Can I write an assignment operator for my Vertex class, if so what would a sample declaration line look like?


NOMAD