vendor material info record

hi,

When am trying to create vendor material info record,i see the<b> valid to</b> is <b>mandatory feild</b> but it is <b>disabled .</b>.

i cannot enter any value in that.

i:e In <b>T/C me11</b> after i enter the details in the first screen,click enter it takes to the next screen. In that screen you can see conditions area you can see Net price and to its side you can see valid to that feild is mandatory feild but its blocked or disabled from entering values.

hope you can understand guys,what and where am navigating.

Thanks and regards

Rajasekaran.