Help regarding finding the values below intersect value from two different dimension matrix

I want to know how can I obtain the value less than intersection value between two different dimension matrix. for example i have matrix a=[1;2;5;6;89;90] and matrix b=[5;89;90;100]. I want to get if any one value in the two matrix are same then output should be value below that value in matrix a. In this case the a and b matrix has first common value as 5 so my out put matrix should give me c=1;2.

Answer 1

[madhan ravi]

 a(1:find(ismember(a,b))-1,1)

[Tukaram Zore]

Thank You.