TextBox.Attributes - outputting an &

I have a textbox that I add an attribute to
txtBox.Attributes.Add("onkeypress", @"alert(value > 1 && value < 58);");
When the page is created I cannot get the string to output the "&", it converts it to &amp and the "<" to &lt
Any idea how I can achieve what I'm trying to do.
Cheers
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