Jtable and MySql

[skyot]

I'm getting and error when i'm try to do the below coding. I can't understand the this netbeans error. The error is as follows.\[code\]Mar 21, 2013 2:28:19 AM timetable.generator.JFTTGenerator6 jButton2ActionPerformedSEVERE: nulljava.sql.SQLException: Before start of result setat com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1073)\[/code\]Please help me !!!!\[code\]String subj=(String) jTable1.getValueAt(0,1 );Connection con = Driver.connect();ResultSet lec1=Handler.getData(con,"select lec_id from lecdetails,subjects where subjects.sub_code=lecdetails.sub_code and subjects.sub_name='"+subj+"'");ResultSet rst1= Handler.getData(con, "select sub_name from subjects,lecdetails where subjects.sub_code=lecdetails.sub_code and subjects.sem='2nd' and lecdetails.lec_id <> '"+lec1.getString(1) +"' order by rand() limit 1 ");jTable2.setValueAt(lec1.getString(1), 0, 1);\[/code\]