Set dispatcherTimer_Tick with combo box

Question

hello there,

I'm newbie in wpf application. I want to ask how to set dispatcherTimer.tick value from combo box. I have cboMinutes, the value is "10","20","30".

And now i want to set my dispatcherTime.Tick value is same with my cboMinutes value. so if i choose cboMinutes to "10", my dispatcherTimer.Tick value is 10. 

Can someone help me please ? ?