Big Problem with WYSI-WordPress plugin

I activated this plugin and it bring advanced WYSI
editor when try to write but as soon as I take mouse
to writing area, it keep on popping that script error
dialog for line 1 char 1 and does not let me type a
single word.

Then I deactivated the plugin, my normal wysi editor
did not return. I try to activate the plugin again,
still no wysiwyg editor returns. ONLY BLANK TEXTBOX
FOR WRITING APPEARS NOW.

How to atleast take my old wysiwyg editor back ?