dynamic form field names

[taz6053]

I have a form with textfields that are dynamically created and named from a recordset. There are 2 textfields created by each record Ex. sAccountId1, sAmount1 and are incremented based on the number of records. The record count is stored in another textfield. I need to use javascript to add up all of the sAmount1 thru sAmount...20 when one of those textfields change. I have tried using a for loop but am not real sure how to do this. I am really new to javascript. I have mostly been programming in vbscript in the past.

Any help would be appreciated.

 

[dwarfthrower]

The following will return the total of all text fields where the first seven characters of the name attribute are "sAmount".

function getTotal(){
 var myForm = document.getElementById("myFormID");
 var allAmounts = myForm.getElementsByTagName("input");
 var total = 0;
 for(var i = 0; i < allAmounts.length; i++){
  var currField = allAmounts.item(i);
  if(currField.type == "text" && currField.name.slice(0,7) == "sAmount"){
   total = total + parseFloat(currField.value);
  }
 }
 return total;
}

- Provided of course that all those values are numeric. If a user enters text in there it will spit our a NaN (Not a Number). Adding some error checking like:

  var currFieldVal = parseFloat(currField.value);
  if(isNaN(currFieldVal)){
   alert("Unable to convert value to number in field " + currFieldVal.name);
  }
  else{
   total = total + currFieldVal ;
  }

Would help if you don't already have some functionality in there enforcing numeric only values.

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There's nothing the world loves more than the taste of really sweet dreams.}
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[taz6053]

Thanks for your help but I am getting an error the error 'null' is null or not an object. By prcess of elimination the line getting this error is var allAmounts = myForm.getElementsByTagName("input");

 

[trollacious]

What is the code you have for the line before that?

Lee

 

[taz6053]

var myForm = document.getElementById("myFormID");

I copied the code exactly from what you wrote above.

 

[dwarfthrower]

Right... and your form's ID just so happens to be "myFormID"?

Try replacing that with the actual ID of your form (sorry, but telepathy is not my strong suit).

_{Never be afraid to share your dreams with the world.
There's nothing the world loves more than the taste of really sweet dreams.}
Enable Apps

 

[taz6053]

Thanks again. I had tried changing that but wasn't sure what to change it to. Below is what I ended up with and it is working.

<SCRIPT LANGUAGE="JavaScript">
<!-- Begin
function s(num) {
amount = num * 1; // amount is the num or NaN

if (isNaN(amount)) { // if the entire is not a number

alert(
"' " + num + " ' is not a valid entry for that field."
);

return 0;
}
else
return amount; // if it is OK, send sum back
}

function r2 {
//round all values to 2 decimal places
ans = (Math.round(n * 100))/100 + ""
dot = ans.indexOf(".",0)
if (dot == -1) {ans = ans + ".00"}
else if (dot == ans.length - 2) {ans = ans + "0"}
return ans
}



function locked(a) {
window.event.returnValue=false
alert("This is a calculated field.")
}

function getTotal(form){

var myForm = document.getElementById("InvAdd");
var allAmounts = myForm.getElementsByTagName("input");
var total = 0;
for(var i = 0; i < allAmounts.length; i++){
var currField = allAmounts.item(i);
if(currField.type == "text" && currField.name.slice(0,7) == "sAmount"){
var sAmt=s(currField.value);
currField.value=r2(sAmt)
total=total + sAmt;
}
}

form.sum.value=r2(total)
}

// End -->

 

[trollacious]

I think I'm half psychic and half psycho, and that's why I thought the line before had an error in it. #

Lee