如何在格点上为用splom绘制的相关系数增加p值?

I am making a scatterplot matrix using lattice and plotting the correlation coefficients of 12 variables in the upper half of the panel. I would also like to add the p values beneath the correlation coeffiecients or stars indicating their level of significance. Here is my R code. How can I achieve this? Many thanks in advance!I am making a scatterplot matrix using lattice