You renamed "input" to "Calculator_input", but forgot to rename it in the functions
PHP Code:
function Calculator_one.onAction()
{
if(Calculator_input.text == 0)
{
Calculator_input.text = 1;
}
else
{
Calculator_input.text @= 1;
}
}
Also, make sure you use "==" when comparing variables instead of "="; a single equality sign is used for assigning values to variables, and two signs are used for comparisons.
edit: damn you Chompy 