alternative to toFixed returns weird result

[EwS]

I came across different posts that talk about alternatives to toFixed, which doesn't work in Safari. However, I didn't find a solution that would really work for me - I don't want to hardcode any decimal places, I want to pass it as an argument to a function. And I found a function on another site, which supposed to work on both Explorer and Safari; the thing is that it does work in Explorer (returns '300.00'), but in Safari I get this weird result: '300function pad(s) { s= s || "."; return s.length > n ? s : pad(s+"0");'

This is the function definition:

Number.prototype.toDecimals=function(n){
    n=(isNaN(n))?
        2:
        n;
    var nT=Math.pow(10,n);
    function pad(s){
            s=s||'.';
            return (s.length>n)?
                s:
                pad(s+'0');
    }
    return (isNaN(this))?
        this:
        (new String(
            Math.round(this*nT)/nT
        )).replace(/(\.\d*)?$/,pad);
}

This is how I call the function:

var myNumber=300, formattedNumber=myNumber.toDecimals(3);

 

[EwS]

Sorry, I made a typo - the correct result from Explorer is '300.000', not '300.00'.

 

[EwS]

This works (you just pass the name of the text box and number of decimal places):

// Format the input 
//
formatNumeric(document.myForm.myTextBox,3);

function formatNumeric(t,decimal) {
  // verify the input is numeric
  if (isNaN(t.value)) {
    t.value = "0";
  }
  var nT=Math.pow(10,decimal);
  var sValue = Math.round(t.value * nT) + "";
  if (sValue == 0) {
    sValue = pad(decimal+1,t.value.toString(),'0');    
  }
  a = new Array();
  a = sValue.split(".");

  // there's already a decimal point in the string
  if (a.length == 2) { 
    return;
  }

  var sPart1 = sValue.substr(0, sValue.length-decimal);
  var sPart2 = sValue.substr(sValue.length-decimal);
  var s = sPart1+"."+sPart2;
  t.value = s;
}


// Pad a string
//
function pad(length,string,filler) {
  if (length <= string.length) {
    return string;
  }
  max = length - string.length;

  for (var i = 0; i < max; i++)  {
    string += filler;
  }
  return string;
}