Page Parameter Seeded ELs doesn't work

Question

hi Experts,
I am using wcp11ps7, I need to use page template to retrieve value of page parameter, I used seeded EL in page template like this:
page
page attributes:
${pageDocBean.title}
${bindings.leftWidth}
the page title has been retrieved properly, but for bindings.leftWidth,returned value is empty, I also tested with the following:
${bindings.centerWidth}
${bindings.showHeader}
${bindings.showFooter}
but I got the same empty value, what's wrong with my test?
Best regards

Answer 1

OS X Mavericks: Reset your computer’s PRAM
A small amount of your computer’s memory, called “parameter random-access memory” or PRAM, stores certain settings in a location that OS X can access quickly. The particular settings that are stored depend on your type of Mac and the types of devices connected to it. The settings include your designated startup disk, display resolution, speaker volume, and other information.
Note: To print these instructions, open Help Viewer’s Action pop-up menu (looks like a gear), then choose Print. 
Shut down your Mac.
Locate the following keys on the keyboard: Option, Command (⌘), P, and R. You will need to hold these keys down simultaneously in step 4.
Turn on your Mac.
Immediately press and hold the Option-Command-P-R keys. You must press this key combination before the gray screen appears.Continue holding the keys down until your Mac restarts, and you hear the startup sound for the second time.
Release the keys.
Resetting PRAM may change some system settings and preferences. Use System Preferences to restore your settings.