EXT JS- TextField condition for Not a pattern

EXT JS- TextField condition for Not a pattern

i am new to EXT JS . Consider the declaration of a Textfield below
{
xtype: 'textfield'
,id:'lcfirstname'
,name: 'lcfirstname'
,maxLength: 100
,regex:/^\s*[a-zA-Z0-9-_]*$/
}
i can able to write pattern based on the pattern what and all can be typed
in text field. but i need to write pattern in the text field such that the
text field should not take those pattern
(i.e. not of regex like that anything is there in EXT JS?). the pattern
can include all the special symbols.