Running total in textbox in asp.net

hello guys how r u ?

i am in trouble ,, my question is that, i have 4 textboxes and 1 resultant textbox now i want , when user come having enter values in 4 textboxes with using tab button then the sum of that textboxes come in resultant textbox ...

how can i make it possible for me in asp.net

reply soon

Thanks

Here is a sample code using javascript, if your requirement is some thing other than this let me know

Desgin

ErrorMessage="*" ToolTip="Only numbers" ForeColor="Red" Display="Dynamic" ValidationExpression="^(\d+)?$">	ErrorMessage="*" ToolTip="Only numbers" ForeColor="Red" Display="Dynamic" ValidationExpression="^(\d+)?$">	ErrorMessage="*" ToolTip="Only numbers" ForeColor="Red" Display="Dynamic" ValidationExpression="^(\d+)?$">	ErrorMessage="*" ToolTip="Only numbers" ForeColor="Red" Display="Dynamic" ValidationExpression="^(\d+)?$">

Javascript

Page load do this

protected void Page_Load(object sender, EventArgs e)

{

if (!IsPostBack)

{

txt1.Attributes.Add("onBlur", "return multiplication('" + txt1.ClientID + "','" + txt2.ClientID + "','" + txt3.ClientID + "','" + txt4.ClientID + "')");

txt2.Attributes.Add("onBlur", "return multiplication('" + txt1.ClientID + "','" + txt2.ClientID + "','" + txt3.ClientID + "','" + txt4.ClientID + "')");

txt3.Attributes.Add("onBlur", "return multiplication('" + txt1.ClientID + "','" + txt2.ClientID + "','" + txt3.ClientID + "','" + txt4.ClientID + "')");

txt4.Attributes.Add("onBlur", "return multiplication('" + txt1.ClientID + "','" + txt2.ClientID + "','" + txt3.ClientID + "','" + txt4.ClientID + "')");

}