Error with Eclipse ADT

Question

I had installed every think correctly SDK,JRE ect..... and I tryied many solution from youtube but doesn't work . there is an error sign on appcompat_v7 and an excalamtion on my project I used to work with Eclipse on java project perfectly unless I installed ADT,errors came up.

(4 Errors )Description :

1. error: Error retrieving parent for item: No resource found that matches the given name 'android:Widget.Material.ActionButton'. styles_base.xml /appcompat_v7/res/values-v21 line 75 Android AAPT Problem

2. The container 'Android Dependencies' references non existing library 'C:\Users\ayman\workspaceJavaMars\appcompat_v7\bin\appcompat_v7.jar' HappyBirthday Build

   path Build Path Problem

3. The project cannot be built until build path errors are resolved HappyBirthday Unknown Java Problem

4. Description Resource Path Location Type Unparsed aapt error(s)! Check the console for output. HappyBirthday line 1 Android ADT Problem