I need to call 2 functions onkeypress out of which first function is return type; and second function is not getting called but if use in reverse order it is working

Requirement:

OnKeyPress, the key should be validated. if number, accept the value in TextBox then copy the value into another textbox; If not a number, then do nothing

Correct Order but 2nd function is not getting called;

<input type="text" name="no_of_units" id="no_of_units" size="5" 
onkeypress="return isNumberKey(event);calc_exchange();">

In Reverse order both functions are working. I need the isNumberKey function to be called first.

<input type="text" name="no_of_units" id="no_of_units" size="5"
 onkeypress="calc_exchange();return isNumberKey(event);"

Functions :

function isNumberKey(evt)
      {
         var charCode = (evt.which) ? evt.which : event.keyCode
         if (charCode > 31 && (charCode < 48 || charCode > 57))
            return false;
         return true;
      }
function calc_exchange()
{
var raw1=document.getElementById("no_of_units").value;
document.getElementById("next_no_of_units").value=raw1;
}

I need the following order of function to be called;

1. return isNumberKey(event)
2. calc_exchange()

I need to call 2 functions onkeypress out of which first function is return type; and second function is not getting called but if use in reverse order it is working

Requirement:

OnKeyPress, the key should be validated. if number, accept the value in TextBox then copy the value into another textbox; If not a number, then do nothing

Correct Order but 2nd function is not getting called;

<input type="text" name="no_of_units" id="no_of_units" size="5" 
onkeypress="return isNumberKey(event);calc_exchange();">

In Reverse order both functions are working. I need the isNumberKey function to be called first.

<input type="text" name="no_of_units" id="no_of_units" size="5"
 onkeypress="calc_exchange();return isNumberKey(event);"

Functions :

function isNumberKey(evt)
      {
         var charCode = (evt.which) ? evt.which : event.keyCode
         if (charCode > 31 && (charCode < 48 || charCode > 57))
            return false;
         return true;
      }
function calc_exchange()
{
var raw1=document.getElementById("no_of_units").value;
document.getElementById("next_no_of_units").value=raw1;
}

I need the following order of function to be called;

1. return isNumberKey(event)
2. calc_exchange()

• javascript
• html
• css

• 2 return means done!go back so no statement after return will be executed. – Arpit Commented Jan 20, 2013 at 12:54
• is there any function afterKeyPress ? – logan Commented Jan 20, 2013 at 13:16
• nope! but you can use onkeydown and onkeyup events. – Arpit Commented Jan 20, 2013 at 16:46

4 Answers 4

You can call two javascript functions on keypress where first function is a return type function.

<input type="text" name="txtName" id="txtName" size="5" 
Onkeypress="return isNumberKey(event,this) && clickButton(event,'imgbtnSearch')">

using && operator, we can call two javascript functions on keypress.

Calling return will execute what's on the right of it and then exit, so naturally the second function is not getting called.

It's hard to answer without knowing what's inside your functions. But I would suggests you attach event handlers with JavaScript and not inline like you are doing. You will get more control that way.

Look here for how to attach event handlers: http://www.quirksmode/js/events_advanced.html

So you can't call anything after return therefore you can try this. if wrong input raise alert.

<input type="text" name="no_of_units" id="no_of_units" size="5" 
onblur=calcexchange() onkeypress="isNumberKey(event)">
....
function isNumberKey(evt)
      {
         var charCode = (evt.which) ? evt.which : event.keyCode
         if (charCode > 31 && (charCode < 48 || charCode > 57))
            alert("Wrong I/P");
             evt.focus()
      }

The return doesn't have to be the first statement. Just call the function in order and return the result later.

<input type="text" name="no_of_units" id="no_of_units" size="5" 
onkeypress="var result = isNumberKey(event); calc_exchange(); return result;">

Returning the result of isNumberKey may prevent the default action, if it returns false the input will be ignored. It seems you want prevent non-numbers and execute calc_exchange. In this case you should only return false if the input is no number:

if(!isNumberKey(event)) { // validate input
  return false; // it's not a number, so prevent default action (do nothing)
}
calc_exchange(); // it was a number, copy the value

The only problem is, at the time you execute calc_exchange, the entered number hasn't been inserted into the textbox's value. You could listen to other events though, like when the user input was done:

<input type="text" name="no_of_units" id="no_of_units" size="5" 
onkeypress="return isNumberKey(event);"
onchange="calc_exchange();" >