How I can give option in popup when send an email in ASP.NET

Question

hi i need help to give an pop up to select attachment PDF or excel
how I can give please help me

protected void btnEmailwithPDF_Click(object sender, ImageClickEventArgs e)  {       Email_excel(true); }

 i want to give option to send email with pdf attachment or excel attachment

Actually report in GridView exporting in PDF and EXCEL, so when I am going to click on Email button that time I want to give options as radio button PDF attachment or EXCEL Attachment,by default attachment is going Excel but i want to give option.


like i want if client select PDF attachment then send email with attachment with PDF and if client select excel then send Email with excel attachment.

please help me how I can achieve this