WPF datagrid column width

Hi,

I am using wpf data grid in one of my projects, i am setting the column width from my xaml.cs file

datagrid.columns[0].width = 100;
datagrid.columns[1].width = 200;

Now when i drag the column and increase the column width, check the column width it is still displaying me the old column width i.e. 100 and 200. But it should have given me the new column width as i have dragged the column and increased the width.

Can anyone help me in finding a way out of this.

Thanks,
Rajeeva