Apps Error in an XML file: aborting build for my new app!

[Asma2014adk]

Hello guys,
it may sound an easy question but I have trying to fix it for a couple of days and no result yet.
This is my very first app and I get this error no matter what I do.
here is the source code for my app.
In "activity_main.xml" file I have :

<RelativeLayout xmlns:android="ht"t"p://schemas.android.com/apk/res/android"
xmlns:tools="ht"t"p://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android: paddingBottom="16dp"
android: paddingLeft="64dp"
android: paddingRight="64dp"
android: paddingTop="16dp"
tools:context="com.davidgassner.myfirstapplication.MainActivity" >

<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/F_app" />

<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/F_B" />

</RelativeLayout>


and here is the source code in strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources xmlns:android="ht"t"p://schemas.android.com/apk/res/android">

<string name="app_name">My First Application</string>
<string name="hello_world">Hello world!</string>
<string name="action_settings">Settings</string>
<string name="F_app">This is my first android application!</string>
<string name="F_B">And this is a clickable button!</string>

</resources>

Notes:
1) I do not have any .out.xml file in res/layout.
2) I have added this:
<?xml version="1.0" encoding="utf-8"?>
to the beginning of the activity_main.xml file but the error is still there.
3) in the code above you see ht"t"p, that is because I am new on this page and I am not allowed to post a link.

I really need your help.
Many thanks