Applet to database error

Hi...
I had an application where i need to connect to the database for the values to display in the applet....
Following is a part of that...
The code works fine in the local system..
but when its not working over the net..
When i placed this in the server,
The local system is displaying null values as the result...

<code>
public class circuit extends Applet implements MouseListener{
boolean rect1Clicked,rect1Clicked1,mouseEntered;
RTextLine text = new RTextLine();
Connection con=null;
Statement stmt,stmt1,stmt3;
ResultSet rs,rs2;
String str1,str2,str3,str4,s1,str5,str6;

public void init(){

setBackground(Color.black);
addMouseListener(this);
text.setDrawingComponent(this);

try{

Class.forName("com.mysql.jdbc.Driver");
con=DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb","username","password";);
stmt=con.createStatement();
stmt1=con.createStatement();
stmt3=con.createStatement();



}
catch(Exception e){
e.printStackTrace();
}



}

public void mouseClicked (MouseEvent me) {

int xpos= me.getX();
int ypos= me.getY();


if(xpos>=25 && xpos<=35 && ypos>=540 && ypos<=645)
{
s1="Feeder";
rect1Clicked=true;

}
else
rect1Clicked = false;
res(s1);
repaint();
}
public void paint(Graphics g) {
....Some Painting Lines Code Here....
if (rect1Clicked)
{

g.setColor(Color.red);
g.drawString("("+str1+", ",80,690);
...Some Painting Lines Code Here...
}
public void res(String s) {
try{
str1=null;;
String mid=null;

ResultSet rs3=stmt3.executeQuery("select mid from table1 where lname='"+s+"';");
if(rs3.next()){

mid=rs3.getString("mid");

}
ResultSet rs = stmt1.executeQuery("select Frequency,RPhaseVoltage,ActivePower from mydb.instantaneousdata where meterid='"+meterid+"';");
rs2 = stmt.executeQuery("SELECT ActiveExportTotal,StartDate,StartTime FROM mydb.energysnapshotdata where mid='"+mid+"';");

while(rs.next()){
str1 = rs.getString("Frequency");
str2 = rs.getString("RPhaseVoltage");
str3= rs.getString("ActivePower");


}
while(rs2.next())
{
str4=rs2.getString("ActiveExportTotal");
str5= rs2.getString("StartDate");
str6= rs2.getString("StartTime");
}

}
catch(Exception e){


}
}
}
</code>


This is my code....

There r some code left which i didn't included in the above code...as it is a very large code which isn't necessary for finding the error...
as itz only drawing strings or lines...

PLs help..
thanx in advance