根据文化显示正确的日期格式

I am using a control for a popup calendar date picker. This uses a javascript function, SetText, to set the textbox to the given date. I can't change anything in the calendar control itself but I can override the SetText function. The SetText javascript just takes the TextBox name and the date value in string format and sets the TextBox to the string. I am using a control for a popup calendar date