R无法解析-Android错误

问题：

I just downloaded and installed the new Android SDK. 我刚刚下载并安装了新的Android SDK。 I wanted to create a simple application to test drive it. 我想创建一个简单的应用程序来测试驱动器。

The wizard created this code: 向导创建了以下代码：

package eu.mauriziopz.gps;

import android.app.Activity;
import android.os.Bundle;

public class ggps extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
}

but Eclipse gives me the error 但是Eclipse给了我错误