You have global variable: string[,] tsReqs;
and have local variable:
private void button1_Click(object sender, EventArgs e)
{
.....
//This is NOT global variable initilization!!!!!!
string[,] tsReqs = new string[rowCount, colCount];
//.....
for (int i = 1; i <= rowCount; i++)
{...
}
}
So on your button1
click you initialize local variable, but on button3
click you refer to global variable.