$return = array();
switch($_REQUEST['action']){
    case 'register':

        $v = true;
        $fields =   array('u_first_name', 'u_last_name');
        foreach($fields as $f)
            ${$f} = $_REQUEST[$f];

        $image_file = $_FILES['profile_image'];

    //validate, upload image and manipulate db
}

submit_button.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {

            Boolean f;
            Boolean i;

            //Get All Fields
            Edi_First_Name          = (EditText)findViewById(R.id.Edi_First_Name);
            Edi_Last_Name           = (EditText)findViewById(R.id.Edi_Last_Name);
            image_preview           = (ImageView)findViewById(R.id.Reg_Profile_Image_Preview);

            //check if any fields are empty, if not proceed to api, else show errors
            f = Function.notEmpty("First Name", Edi_First_Name);
            f &= Function.notEmpty("Last Name", Edi_Last_Name);

            //check if image has been set
            i = Function.imageNotSet(image_preview);
            f &= i;

            if(f == true){
                //if everything is validated,talk to api.

                String first_name, last_name, company_name, job_title, email, contact, address_one, address_two, town, county, postcode, country, account_email, rep_account_email, account_password, rep_account_password;

                first_name          = Function.getEditText(Edi_First_Name);
                last_name           = Function.getEditText(Edi_Last_Name);

                //pass parameters so that we can call the register api via FUNCTIONS.java
                Function.registerCall(first_name, last_name, "test_image");
            }
            else{
                Toast.makeText(getApplicationContext(), "Error.", Toast.LENGTH_SHORT).show();
            }
        }
    });