You need to match up the names of the input fields/parameters to the names of the attributes in your bean.
e.g. your textfield for name is currently called "txt_name"
This will look for the method setTxt_name() in your bean which doesn't exist.
I would suggest:
I also note that contact is an int in your bean.
You are submitting contact from a textfield, which means there possibly needs to be validation/conversion on that field to turn it into an int. What happens if the user doesn't provide a valid number?
subject: getting null values, when displaying values using usebean