please suggest data type for decimal value

Question

i am trying to pass a decimal value through a textbox and want to store into a sql table i am trying this code but it is giving error

"input string was not in current format"

please suggest is there any thig issue in this or what code is better to use for

my code is as below

 

string total = textBox10.Text;  

double itotal = Int64.Parse(total);