document.getElementById is 'undefined' for Firefox only - IE works!

When I run this code in Firefox this line returns 'undefine'....

document.getElementById("<% =lblUserRole.ClientID %>").innerText

I can view source and see the control.  In IE it works fine.  I've attached the code....

The control should be 'ctl00_ContentPlaceHolder1_lblUserRole' in View/Source.
function OnClientAppointmentResizeStart(sender, eventArgs)  
    {  
        try {
            if (document.getElementById("<% =lblUserRole.ClientID %>").innerText != "999" && document.getElementById("<% =lblUserRole.ClientID %>").innerText != "500")
            {
                // this line returns undefined in FF only!
                alert(document.getElementById("<% =lblUserRole.ClientID %>").innerText);
                alert("You do not have permission to dynamically resize this appointment.");
                eventArgs.set_cancel(true);
            }
            else{
                eventArgs.set_cancel(false);
            }
        } catch(e) {
            alert("OnClientAppointmentResizeStart error:" + e);
        }
        
    }

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LVL 9
RobertNZanaAsked:
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David S.Connect With a Mentor Commented:
innerText is a proprietary IE property.

firstChild.nodeValue might be the simplest cross-browser alternative.

innerHTML would be another alternative.
0
 
LordOfPortsCommented:
The element you are referencing most likely does not have an id attribute, only the name attribute. In IE the getElementById function defaults to the name attribute if it cannot find an element with the specified id, FF does not, e.g. the following example works in IE but not in FF:

<input type="text" name="txtTest" value="Test" />
<input type="button" value="Get Value" onclick="alert(document.getElementById('txtTest').value);" />

Add the id attribute to the element and it should become cross browser compatible.
0
 
LordOfPortsCommented:
Sorry, my post refers to a different problem, Kravimir's solution is the correct one for your problem.
0
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