Function tagName not on JQuery object causing "Cannot read property 'toLowerCase' of undefined"

[DarkSnowy]

Form.Element function getValue is throwing
"VM43674 prototype.js:6476 Uncaught TypeError: Cannot read property 'toLowerCase' of undefined
at getValue (VM43674 prototype.js:6476)
at Object.insert (VM43675 insertLink.js:11)
at InsertLink (selectLink.aspx:44)
at :1:2"

Prototype.js build version 1.7.3

This is due to wrapping the element in a JQuery object and then trying to directly access a property of the element.
Removing the JQuery wrapper fixed it for me but you may want to use element.prop("tagName").toLowerCase();. If you take the src in that direction then be wary that many of the functions the element are passed into will not expect a JQuery object and will also throw errors.