Domain Availablity

Hi everyone....is there any one having idea of domain check availability code in asp.net using C#....
    I have a TextBox where user can enter the domain name as their own.....and the next control is the DropDownList where user can select the extensions like .org,.com,.net etc and these is a check button and once if any one hit the check button it shows whether the domain is available or not...and it should shows the result in the label..If anyone can help me out..and surely it will be appreciated...Advance thanks....

 Note:Its very urgent for me to show my final year engineering project