[RESOLVED] Best to way to trap NullException

[dr_aybyd]

Hello. Anybody can suggest whats the best way to trap the null exeption from this code of mine.

long last_Sent;
        long last_Rec;
 
        private void timerPackets_Tick(object sender, EventArgs e)
        {
            try
            {
                string strSent = null;
                string strReceived = null;
                long strStatdon;
                long strStatup;
                long curr_Sent = 0;
                long curr_Rec = 0;
                long speedDown = 0;
                long speedUp = 0;
 
                
                strSent = clsMethods.strLines(5);
                strReceived = clsMethods.strLines(4);
                string[] arrSent = strSent.Split(',');
                string[] arrRec = strReceived.Split(',');
                curr_Sent = long.Parse(arrSent[1]);
                curr_Rec = long.Parse(arrRec[1]);
                speedDown = curr_Rec - last_Rec;
                speedUp = curr_Sent - last_Sent;
                strStatdon = speedDown * 8;
                strStatup = speedUp * 8;
                StatusDown.Text = clsMethods.convertSize(strStatdon) + " /s";
                StatusUP.Text = clsMethods.convertSize(strStatup) + " /s";
                lblUP.Text = clsMethods.convertSize(last_Sent);                
                lblDown.Text = clsMethods.convertSize(last_Rec);
                last_Rec = long.Parse(arrRec[1]);
                last_Sent = long.Parse(arrSent[1]);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString(),"Information");
            }

For I just popup the error being generated.
On my code sometimes this two line
strSent = clsMethods.strLines(5);
strReceived = clsMethods.strLines(4);
doesn't return a value.
that's why this line
string[] arrSent = strSent.Split(',');
string[] arrRec = strReceived.Split(',');
throw me an exeption.
I want when nullreference error occured just to continue the timer tick until that two line have value in it..

THanks.
br.