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"TypeError: XMLHttpRequest.Open is not a function" error message

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I have the following javascript code:

var XmlHttp = new XMLHttpRequest();
XmlHttp.Open("GET", "http://localhost/MenuOptions.aspx?ca_key=1631&isRollup=1", false);

In Firefox (version 22) the XmlHttp.Open() throws an error "TypeError: XmlHttp.Open is not a function"

I have the following javascript code: <pre><nowiki>var XmlHttp = new XMLHttpRequest(); XmlHttp.Open("GET", "http://localhost/MenuOptions.aspx?ca_key=1631&isRollup=1", false);</nowiki></pre> In Firefox (version 22) the XmlHttp.Open() throws an error "TypeError: XmlHttp.Open is not a function"

cor-el modificouno o

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All Replies (5)

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is this a script error or stopage, does safe mode fix the problem

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Safe mode does not fix this problem.

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Chosen Solution

It seems to be "open" with a lowercase "o":

See:

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I finally figured it out. The functions are case sensitive. So my XmlHttp.Open(<...>) was throwing an exception that Open is not a function. The same happened to me later on with XmlHttp.Send(null). It also said that Send is not a function but when I changed them to XmlHttp.open(<...>) and XmlHttp.send(null) then everything worked fine. So both functions need to start with a lower case letter.

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Hi bbatl, as a general rule, JavaScript objects/functions and DOM objects/properties/methods are case sensitive. This may not apply to some Microsoft technologies which are more forgiving.