Auto Multiply Two Column In Gridview

HI, I need to calculate values of two textboxex in gridview and display the result in the third textbox using javascript as soon as the value entered in second textbox. my textbox

Solution 1:

you should change string to int (as value of any textbox returns string) before multiplication :)

try this :-

txt1.Attributes["onKeyup"] = "javascript: return multiplication('" +  Convert.ToInt32(txt1.Text) + "','" +  Convert.ToInt32(txt2.Text) + "','" +  Convert.ToInt32(txt3.ClientID) + "')";
txt2.Attributes["onKeyup"] = "javascript: return multiplication('" +  Convert.ToInt32(txt1.Text) + "','" +  Convert.ToInt32(txt2.Text) + "','" +  Convert.ToInt32(txt3.ClientID) + "')";

In script :-

<Script type="text/javascript">
 function multiplication(Qty,Rate,txt3)
    {
    //Your logic for multiplication

    document.getElementById(txt3).value=Qty*Rate;       
    }
</script> 

Solution 2:

The problem is with these lines of code

txt1.Attributes["onKeyup"] = "javascript: return multiplication('" + txt1.ClientID + "','" + txt2.ClientID + "','" + txt3.ClientID + "')";
txt2.Attributes["onKeyup"] = "javascript: return multiplication('" + txt1.ClientID + "','" + txt2.ClientID + "','" + txt3.ClientID + "')";

Use Add method instead

txt1.Attributes.Add("onKeyup", "javascript: return multiplication('" +
     txt1.ClientID + "','" + txt2.ClientID + "','" + txt3.ClientID + "')");
txt2.Attributes.Add("onKeyup", "javascript: return multiplication('" +
     txt1.ClientID + "','" + txt2.ClientID + "','" + txt3.ClientID + "')");

and also do parseInt() in javascript

var Qty  = parseInt(document.getElementById(txt1).value);
var Rate = parseInt(document.getElementById(txt2).value);