It's sometimes required to disable cut,copy and paste for Textbox control on web page,mostly for passwords.
To achieve such things,simply write:-
//For Disabling Cut Option
<input type="text" oncut = "return false;" />
//For Disabling Copy Option
<input type="text" oncopy = "return false;" />
//For Disabling Paste Option
<input type="text" onpaste = "return false;" />
//For Disabling All options i.e. Cut,Copy and Paste for Textbox
<input type="text" oncopy = "return false;" onpaste = "return false;" oncut = "return false;">