How to Call a Server side Function on the Client side Pin

[vuyiswamb]

Good Day All

i have a Function e.g

public String Getdata(String mystr)

{

//Do what ever

//return  a String

}

and i want to call this function and pass data in Javascript like this

function KeyPress() {
            var TExtbox1 = document.getElementById('Text1');
        
         if (TExtbox1.value.length == 2) {

        //call the function here and pass the textbox1 value.  

   return false;
         }
        }

Thanks