wont reflach prom keeps giving eror

here is my problem i tried to upload a program and it keeps giving me this

Arduino: 1.5.7 (Mac OS X), Board: "Arduino Micro"

Sketch uses 4,800 bytes (16%) of program storage space. Maximum is 28,672 bytes. Global variables use 157 bytes (6%) of dynamic memory, leaving 2,403 bytes for local variables. Maximum is 2,560 bytes. processing.app.debug.RunnerException: Couldn't find a Board on the selected port. Check that you have the correct port selected. If it is correct, try pressing the board's reset button after initiating the upload. at cc.arduino.packages.uploaders.SerialUploader.waitForUploadPort(SerialUploader.java:197) at cc.arduino.packages.uploaders.SerialUploader.uploadUsingPreferences(SerialUploader.java:91) at processing.app.Sketch.upload(Sketch.java:1714) at processing.app.Sketch.exportApplet(Sketch.java:1625) at processing.app.Sketch.exportApplet(Sketch.java:1597) at processing.app.Editor$DefaultExportHandler.run(Editor.java:2397) at java.lang.Thread.run(Thread.java:745)

This report would have more information with "Show verbose output during compilation" enabled in File > Preferences.

What post comes up when you plug it in? Bring up a terminal window, try dmesg, then plug it in and run dmesg again.