Convert decimal values

Question

I  have a form with 3 textboxes and aslo other tools. in these 3 have decimal values.

in databse ,table have 4 fields (name varchar(),qty decimal(),value decimal(),price decimal()) named item

When we insert the the textbox values into the databse it passes only integer part values not decimal points. i use storedprocedure.

I  use the code like

cn.insert( textbox1.text,Convert.ToDecimal(textBox2.Text), Convert.ToDecimal(textBox3.Text), Convert.ToDecimal(textBox4.Text))
but it takes only integer part. how we insert decimal point values ? plz help.