Unique identifier for GUI-elements in HTML

For the GUI in web, we implement an extension to customize the UI a little bit.
For example some ClearQuest-Ids become linkable directly or some pop-up-windows interact to special value-changes.

For implementing such functionality we have to parse the whole html-tree and analyze the structure with JavaScript to identify the field-types.
Actually it is not possible to identify the different field-typs, which are set on the GUI.

For example to get all Multiline-fields, we are using the following JS-function:

var multilines = rq1Core.getDojo().query(".dijitTextBox");

The problem is, that the result will not return only the Multiline-fields, it also returns String-fields, choicelists etc..
So we have to analyze all returned fields with much effort (analyzing special attributes etc.).

The same problem occurs for pop-up-message-boxes.
The function rq1Core.getDojo().query("#cq_widget_CqMessageDialog_0_desc"); returns only the message-box with the number zero in the attribute-value.
But by getting the message-box again this number is different.

Now we need an attribute at each GUI-element which identifies the element unique.
Possible GUI-elements are:
- choicelist
- multi-choicelists
- text-field (for Short-string)
- text-field (for multiline-string)
- reference-list
- reference
- checkbox
- radio-buttons
- lable
- buttons
- tabs
- groups/frames
- ...