trouble with accumulating a total: windows form

[EDN Admin]

Hi,
i am trying to accumulate a total into my variable of type int called targetTotal which corressponds to my text box called
<span style="font-size:x-small; font-family:Consolas <span style="font-size:x-small; font-family:Consolas totaltargettxtbx which is then meant to be sent to my ms access database via a button submit into a field called targetTotal of type Long Integer, but
when i try to run my form i get an error saying: Input string was not in a correct format. which points to this line
<span style="font-size:x-small; font-family:Consolas <span style="font-size:x-small; font-family:Consolas <span style="font-size:x-small; font-family:Consolas <span style="font-size:x-small; font-family:Consolas
targetTotal =
<span style="font-size:x-small; font-family:Consolas



<span style="font-size:x-small; color:#2b91af; font-family:Consolas <span style="font-size:x-small; color:#2b91af; font-family:Consolas <span style="font-size:x-small; color:#2b91af; font-family:Consolas Convert<span style="font-size:x-small; font-family:Consolas <span style="font-size:x-small; font-family:Consolas .ToInt32(totaltargettxtbx.Text);
<span style="font-size:x-small; font-family:Consolas <span style="font-size:x-small; font-family:Consolas i scoured the net for a while now and i noticed that i have to check for a null value which i am trying to do given the following code:
<div style="color:black; background-color:white
<pre> <span style="color:blue int targetOneDay =0;

<span style="color:blue int targetTwoDay = 0;

<span style="color:blue int targetFiveDay = 0;

<span style="color:blue int targetTenDay = 0;

<span style="color:blue int targetTotal =0;

<span style="color:blue int total = 0;





targetOneDay = Convert.ToInt32(nine_to_fourteenhrstxbx.Text);

targetTwoDay = Convert.ToInt32(fifteen_to_fortfourglhtxtbx.Text);

targetFiveDay = Convert.ToInt32(fourtyfive_to_74txtbx.Text);

targetTenDay = Convert.ToInt32(min75glhtxtbx.Text);

targetTotal = Convert.ToInt32(totaltargettxtbx.Text);



targetTotal += targetOneDay + targetTwoDay + targetFiveDay + targetTenDay;



<span style="color:blue if (totaltargettxtbx.Text != <span style="color:blue null)



total = targetTotal;

<span style="color:blue else

total = 0;

[/code]

<span style="font-size:x-small; font-family:Consolas <span style="font-size:x-small; font-family:Consolas but when doing so i still get the same error message: Input string was not in a correct format. pointing to the same line i.e
<span style="font-size:x-small; font-family:Consolas <span style="font-size:x-small; font-family:Consolas <span style="font-size:x-small; font-family:Consolas <span style="font-size:x-small; font-family:Consolas
targetTotal =
<span style="font-size:x-small; font-family:Consolas


<span style="font-size:x-small; color:#2b91af; font-family:Consolas <span style="font-size:x-small; color:#2b91af; font-family:Consolas <span style="font-size:x-small; color:#2b91af; font-family:Consolas Convert<span style="font-size:x-small; font-family:Consolas <span style="font-size:x-small; font-family:Consolas .ToInt32(totaltargettxtbx.Text);
<span style="font-size:x-small; font-family:Consolas <span style="font-size:x-small; font-family:Consolas please tell me why i get this message and how i can rectify please

full code
<pre lang="x-c# private void submitbtn_Click(object sender, EventArgs e)

{

string projectName;

string startDate;

string endDate;

int targetOneDay =0;

int targetTwoDay = 0;

int targetFiveDay = 0;

int targetTenDay = 0;

int targetTotal =0;

int total = 0;

string dbinsert;


projectName = Convert.ToString(nametxtbx.Text);//nametxtbx.Text;



startDate = startdatetimepcker.Value.ToString();

endDate = enddatetimepcker.Value.ToString();

targetOneDay = Convert.ToInt32(nine_to_fourteenhrstxbx.Text);

targetTwoDay = Convert.ToInt32(fifteen_to_fortfourglhtxtbx.Text);

targetFiveDay = Convert.ToInt32(fourtyfive_to_74txtbx.Text);

targetTenDay = Convert.ToInt32(min75glhtxtbx.Text);


targetTotal += targetOneDay + targetTwoDay + targetFiveDay + targetTenDay;


if (totaltargettxtbx.Text != null)

total = targetTotal;

else

total = 0;



targetTotal = Convert.ToInt32(totaltargettxtbx.Text);





cmd = null;





dbinsert = "INSERT into Project(projectName, startDate, endDate, duration, targetOne, targetTwo, targetFive, targetTen, targetTotal)" +

"VALUES" + "("+""+projectName+""+"," + "" + startDate+""+","+""+endDate+""+","+"5"+","+targetOneDay+"," + targetTwoDay+","+targetFiveDay+","+targetTenDay+","+total+ ")";

cmd = new OleDbCommand(dbinsert, con);

cmd.ExecuteNonQuery();

cmd.Dispose();

con.Close();




}

[/code]



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