Equation Editor

http://www.codecogs.com/components/equationeditor/equationeditor.php Example: \Pr(C_j)=\sum_{i=1}^{I_j}c_{ij}\prod_{k=1}^K\left[\prod_{s=1}^{S_k}\theta_{ks}^{\alpha_{ijks}}\right]\\ \sum_{j=1}^J\Pr\{C_j\}=1;\sum_{s=1}^{S_k}\theta_{ks}=1,c_{ij}\geq0; \alpha_{ijks}\geq 0 \\\\\ s=1,...,S_k;k=1,...,K;i=1,...,I_i;j=1,...,J.