<% int num; String param = request.getParameter("number"); String err = ""; if (param == null){ param="10"; } try { num = Integer.parseInt(param); if (num == 0) { err = "insert null";; }else if (num < 0) { err = "too little"; num = 0; }else if (num > 100){ err = "too many"; num = 100; } } catch (NumberFormatException er){ num = 0; err = "wrong format"; } %>
<%=err%>

Multiplication table <%=num%>x<%=num%>

<% for (int i=1; i<=num; i++) { %> <% for (int j=1; j<=num; j++) { if (i==1 || j==1 ) {%> <% } %> <% } %>
<%}else if (i==j){%> <%}else { %> <% } %> <%= i*j %>