# Add characters : Number Data Type « Language Basics « JavaScript DHTML

```

<html>

<script language="JavaScript">

function myCalc(){

var myLetters = new Array(" ", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j",
"k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u",
"v", "w", "x", "y", "z");
var myNumbers = new Array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26);
var myPreAddends = document.myForm.myInput.value;
var myLowerCase = myPreAddends.toLowerCase();
var mySum = 0

for(i=0; i<myLowerCase.length; i++) {
for (x=0; x<myLetters.length; x++) {
if (myAddend == myLetters[x]) {
}
}

}

document.myForm.myResult.value = mySum;

}

function checkLength() {
var InputCheck = document.myForm.myInput.value
if (InputCheck.length > 15) {

}

}

</script>

<body>

<form name="myForm" onsubmit="myCalc(); return false;">
<p>Please enter up to 15 letters (words, phrases, etc):

<input name="myInput" onkeyup="checkLength()">

<input type="submit" value="Calculate!" name="submit">
<hr>
If a=1, b=2, c=3, etc, then your letters add up to:<br>
<input name="myResult">

</form>

</body>
</html>

```

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