How to check if property 'isElementContentWhitespace' is supported?

Question

I want to use isElementContentWhitespace on text nodes,
but not all browsers support it, so I need to check if its supported,
then if is, use it, if not implement jquery's $.trim...

i've tried doing something like this with no luck on IE, good on FF:

var testEl = document.createElement('span');  
testEl.innerHTML = ' ';  
alert( testEl.firstChild.isElementContentWhitespace );

Answer 1

ok, I've managed to test for this prop!

var testEl = document.createTextNode('text');  
alert('isElementContentWhitespace' in testEl);

works great in IE also... :)