JavaScript Taskbook Level 10.6

Given an input. Make it so that when you type the word 'blur' into it, this input loses focus.

Given a table. Take turns to put all the Tetris figures into it so that the beginning of the figure is in the center of the table.

Modify the previous task so that there are buttons next to the table that can be used to rotate the shapes.

Make a script that generates quadratic equations with integer roots.

Given a textarea. It contains text. The user selects several lines of text and presses the Tab key. Make it so that a tab is inserted at the beginning of each selected line.

Given a string containing any number of nested paired parentheses, write code that will check that the parentheses are positioned correctly.

This is correct:

'()()'

This is correct:

'(())'

This is incorrect, since the number of open brackets does not match the number of closed ones:

'())'

This is incorrect, because although the number of open brackets matches the number of closed ones, they are in the wrong order:

'))(('