Unable to read properties file into feature file

I just created feature file, step definition file and runner class file. Then I added project.properties under src/test/resources and given one property say below - 

browser = InternetExplorer and using the same "browser" keyword in the background of feature file as shown below - 

@RegisterUser
Feature: Register User on online shopping portal

Background:
Given I open browser
And I launch Online Shopping portal
When I click on Sign-In link
Then I am navigated to Sign-up page

@GoToSignUpPage
Scenario: User create an account
Given I am at sign-up page
When I enter the email id
And click create an account button
Then I am taken to create an account page
When I enter the personal and address details
And click Register button
Then I am taken to My Account page

now step definition has below codes - 

public class genericsteps {

@Given("^I open (. *)$")
public void openBrowser(String browserName) {
System.out.println("Opening Browser "+browserName);
}

......... further all the step definition is given which I am showing as ..... here...

.........

.........

.........

}

then when I am running the runner class then I am getting below in the console o/p - 

@RegisterUser
Feature: Register User on automation practice online shopping portal

Background: # src/test/resources/com/webautomation/feature/RegisterUsers.feature:22
Given I open browser # null
And I launch Online Shopping portal # genericsteps.launchsite()
When I click on Sign-In link # genericsteps.clicksigninlink()
Then I am navigated to Sign-up page # genericsteps.signuppage()

@RegisterUser @GoToSignUpPage
Scenario: User create an account # src/test/resources/com/webautomation/feature/RegisterUsers.feature:29
Given I am at sign-up page # genericsteps.registerpage()
When I enter the email id # genericsteps.enteremail()
And click create an account button # genericsteps.clickcreateanaccountbtn()
Then I am taken to create an account page # genericsteps.intocreateanaccountpage()
When I enter the personal and address details # genericsteps.enterdetails()
And click Register button # genericsteps.clickregisterbutton()
Then I am taken to My Account page # genericsteps.myaccountpage()

now if you check in above, Given I open browser # null.......why? it's getting undefined and how to resolve it....

Please suggest urgently....need help to submit small project in 4 days.....

Thank you.