Call a javascript function in a classfile

Hi,
I am having the generic scheduling program in .cs(class file).
How can i call the javascript function in the classfile not in the codebehind(aspx.cs).
In class file the option page.registerclientscriptblock() and button.attributes.add() won't available.
Please check and advise how do we call the java script in classfile.
Thanks in Advance!
P.Sathish Kumar
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