finding the shortest cycle in a graph

hi I am trying to implement the following to find the length of a smallest cycle in a graph G. Please suggest which functions/toolbox are useful for this. I will also be computing how many cycles are there of a particular length. thanks

girth = 1000;
for each edge e(u,v) in G(V,E)
        new_girth = shortestpathlength(G\{e}, u, v) + 1 
                     % shortest distance between u and v
             if (new_girth < = girth)
                girth= new_girth
          G= G U {e}
    end