disable input to cells when a cell has a specified value

From B2 to B11 if any one of the cell input a value of x, the other cells are not allowed to input any value.
Reset B2 to any other value, then other cells are allowed to enter input again

Thanks for the input.
I think I do not post the right question.
I have 5 cells for examples, they are A2, B2, C2, D2 and E2. Only one of the cell can be selected. When one of the cell is selected and input a value of x, then the other cells are disable and cannot enter any value. To enable the other cells again, the cell with value has to be clear.
I know it is easier to use a dropdown but it is a scale to input.

Thank you.

It works, great code, but it is not exactly what I want because I did not make my question clear.

I just want to control 10 cells in the same row. If I enter a value to any one of the cell, the other cells int the same row are locked/disable to enter any value.
When I remove the value of the cell in the row I have inputted, all the cells in this row are unlocked/enabled again.
In this case, one can only enter a value in one of the 10 cells.

Thanks for you help Winon.

The script is very useful but it is not exactly I want.
In the file you attached, when you put a value in L2, from A2 to J2 cells are locked and you can reset L2 for all cells to work again. It is different from what I want.
I need that when I input a value to any one from A2 to J2, except the cell I input a value, the other cells are locked. (for example if I input a value to A2, B2 to J2 are locked but after I clear A2 and I enter a value to B2, then A2, C2 to J2 are locked.

[SOLVED]

Thank you very much Winon.

It is exactly what I needed - excellent way to use data validation.

I cannot add another star as I do not know how to spread the reputation around. I really appreciate you of the immediate help and the excellent answers.