OpenCl C Identifier Undefined

__kernel void distances(constant float* data, int n, int D, int k, global float* centroids,

                       global int* cluster, global float* distances  ){

                    local float l_distances[64];

               private    int idg=(int)get_global_id(0);

                    int idl=(int)get_local_id(0);

                    private double sqdist=0;

                    for(int i=0; i<k;i++){

                            sqdist=0;

                    for (int j=0; j<D;j++){

                        sqdist=fma((double)(centroids[i*D] -data[D*idg+j]),(double)(centroids[i*D]-data[D*idg+j]),sqdist);

                    }

                    l_distances[k*idl+i]=sqrt(sqdist);

                    }

                    private float d_min=0;

                    for(int i=0;i<k;i++){

                            d_min  =d_min<l_distances[k*idl+i]?l_distances[k*idl+i]:d_min;

                            cluster[idg]=d_min=l_distances[k*idl+i]?i:cluster[idg];

                    }

           distances[idg]=l_distances[idl];

}