access label in other form

[algi]

I have two forms and one 1 form there is a button, which does a lot of stuff but there is one problem. I use the below code to access the other from (frmMain)'s label called currentBalance. But at runtime frmMain's label does not change.

frmMain MainForm = new frmMain();
MainForm.currentBalance.Text = "hello";

Why doesn't the label change it's text? In vb this works.