Function help in vb.net 2010 - finding the minimum value in a sequence of numbers separated by commas in one string -

i need create function finds minimum value of sequence of numbers separated commas. whole sequence input 1 textbox(textbox1). me create function uses string search , compares each number eachother , outputs smallest value?

what want can done combination of split method , min method. this:

dim minint double = split(textbox1.text, ",").min(function(i) double.parse(i)) 

of course doesn't validate text in textbox. return lowest numerical value in string describe.