How to refer textbox value in Custom Validator code

I want to write a basic custom validator - to check if the text box value is null or not …

but i dont know how to refer the text box value in the code …

The id of the text box is htmlInputText15 …but stuggling in writing the same in code below .

Does it have to be getFormName.getTextData …?

Is there any PDF or guide on this .

* Validator for the control with id=‘htmlInputText15’
public void htmlInputText15_validator(javax.faces.context.FacesContext context, javax.faces.component.UIComponent component, java.lang.Object value) {

help .

Thanks .

Jasmeen Kaur