why im not able to run selenium with eclipse

hi
im trying to run java code  using eclipse and i get the following error .please someone help me out,,, im new to webdriver

Exception in thread "main" java.lang.Error: Unresolved compilation problems:
    WebDriver cannot be resolved to a type
    FirefoxDriver cannot be resolved to a type

    at runprojpack.runclass.main(runclass.java:6)

hi,

Please install java ,selenium standalone server selenium src along with eclipse and click on build as and select  add an external jar file ,then add all .jar files and selenium standalone and src.Please make sure that it doesn't have compatible issues.


Thanks
arya

i did all still get this error

Exception in thread "main" java.lang.NoClassDefFoundError: org/json/JSONException
    at org.openqa.selenium.firefox.FirefoxProfile.(FirefoxProfile.java:89)
    at org.openqa.selenium.firefox.FirefoxProfile.(FirefoxProfile.java:79)
    at org.openqa.selenium.firefox.FirefoxProfile.(FirefoxProfile.java:67)
    at org.openqa.selenium.firefox.FirefoxDriver.getProfile(FirefoxDriver.java:260)
    at org.openqa.selenium.firefox.FirefoxDriver.startClient(FirefoxDriver.java:236)
    at org.openqa.selenium.remote.RemoteWebDriver.(RemoteWebDriver.java:110)
    at org.openqa.selenium.firefox.FirefoxDriver.(FirefoxDriver.java:190)
    at org.openqa.selenium.firefox.FirefoxDriver.(FirefoxDriver.java:183)
    at org.openqa.selenium.firefox.FirefoxDriver.(FirefoxDriver.java:179)
    at org.openqa.selenium.firefox.FirefoxDriver.(FirefoxDriver.java:92)
    at neww.newwclass.main(newwclass.java:7)
Caused by: java.lang.ClassNotFoundException: org.json.JSONException
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 11 more