Added error checking for element instance

[timwright12]

This was throwing an error for me if there wasn't a UStream player on the page, so I added so checks for those of us who like concatenating all scripts

[necccc]

The code looks ok, the reason is what confuses me.

How exactly the error happen?
If the error occured because create instance was called without the player element, why was it called?
"Concatenating scripts" itself should not result in an error (we use this lib all the time packed with other scripts), the affected code only runs if you invoke it by creating a new instance.