how to resolve "WARNING: Application does not specify an API level requirement"?

Hello I am writing an android application, but as I do run this application, the following application generates and application do开发者_运维问答esn't appear on the windows, please help .. !!!! I will appreciate if I get right solution ,,,,,,

To resolve this warning add

<uses-sdk android:minSdkVersion="4" /> 

to the manifest tag in AndroidManifest.xml. Replace 4 with the lowest number of SDK version you want to support.