Your if statements are all incorrect. In the first case if the total is equal to 120, then it is definitely greater than 50, so it will never go to any of the other tests. So it needs to be reordered to something like:
if (total >= 200))
{
Response.Redirect("quizresult3.aspx");
}
else if (total >= 150))
{
Response.Redirect("quizresult2.aspx");
}
else if (total>= 100))
{
Response.Redirect("quizresult1.aspx");
}
else if (total>50)
{
Response.Redirect("quizresult.aspx");
}
But what happens if the total is 50 or less?
Also note: a single ampersand in your if statements is not correct, it should be
if (expression1 && expression2)
Also using
Convert.ToInt32
on all those text fields will crash your code if any of them contains a non-numeric character. And are you sure you want the values from labels rather than input fields?