Чтоб решение появлялось во время набора цифр
<!DOCTYPE HTML>
<html>
<head> </head>
<body>
<font color="RED" size="18"> <B>КАЛЬКУЛЯТОР</B></font> <br/>
<form name="sci-calc">
<table table border="1" >
<tbody>
<tr>
<td align="center" style="background-color: red" ><input type="button" value="1" onclick="addChar(this.form.display, '1') "></td>
<td align="center" ><input type="button" value="2" onclick="addChar(this.form.display, '2')"></td>
<td align="center" ><input type="button" value="3" onclick="addChar(this.form.display, '3')"></td>
<td align="center" ><input type="button" value="4" onclick="addChar(this.form.display, '4')"></td>
<td align="center" ><input type="button" value="5" onclick="addChar(this.form.display, '5')"></td>
<td align="center" ><input type="button" value="6" onclick="addChar(this.form.display, '6')"></td>
<td align="center"><input type="button" value="7" onclick="addChar(this.form.display, '7')"></td>
<td align="center"><input type="button" value="8" onclick="addChar(this.form.display, '8')"></td>
<td align="center"><input type="button" value="9" onclick="addChar(this.form.display, '9')"></td>
<td align="center"><input type="button" value="0" onclick="addChar(this.form.display, '0')"></td>
<td align="center"><input type="button" value="." onclick="addChar(this.form.display, '.')"></td>
</tr>
<tr>
<td colspan="6" align="center"><input name="display" value="0" size="55" maxlength="55"></td>
<td align="center"><input type="button" value="X" onclick="this.form.display.value = 0 "></td>
<td align="center" ><input type="button" value="<" onclick="deleteChar(this.form.display)"></td>
<td align="center"><input type="button" value="=" name="enter" onclick="if (checkNum(this.form.display.value)) { compute(this.form) }"></td>
<td colspan="3" align="center"><input name="result" size="20" maxlength="20"></td>
<td align="center"><input type="button" value="X" onclick="this.form.result.value = 0 "></td>
<td align="center" ><input type="button" value="<" onclick="deleteChar(this.form.result)"></td>
<td align="center"><input type="button" value="№" onclick="if (checkNum(this.form.display.value)) { sqrt(this.form) }"></td>
<td align="center"><input type="button" value="^2" onclick="if (checkNum(this.form.display.value)) { square(this.form) }"></td>
<td align="center"><input type="button" value="exp" onclick="if (checkNum(this.form.display.value)) { exp(this.form) }"></td>
</tr>
<tr>
<td align="center"><input type="button" value="*" onclick="addChar(this.form.display, '*')"></td>
<td align="center"><input type="button" value="-" onclick="addChar(this.form.display, '-')"></td>
<td align="center"><input type="button" value="/" onclick="addChar(this.form.display, '/')"></td>
<td align="center"><input type="button" value="+/-" onclick="changeSign(this.form.display)"></td>
<td align="center"><input type="button" value="+" onclick="addChar(this.form.display, '+')"></td>
<td align="center"><input type="button" value="(" onclick="addChar(this.form.display, '(')"></td>
<td align="center"><input type="button" value=")" onclick="addChar(this.form.display, ')')"></td>
<td align="center"><input type="button" value="ln" onclick="if (checkNum(this.form.display.value)) { ln(this.form) }"></td>
<td align="center"><input type="button" value="cos" onclick="if (checkNum(this.form.display.value)) { cos(this.form) }"></td>
<td align="center"><input type="button" value="sin" onclick="if (checkNum(this.form.display.value)) { sin(this.form) }"></td>
<td align="center"><input type="button" value="tan" onclick="if (checkNum(this.form.display.value)) { tan(this.form) }"></td>
</tr>
</tbody></table>
</form>
<script>
element.addEventListener('click',compute(form));
function addChar(input, character) {
if(input.value == null || input.value == "0")
input.value = character;
else
input.value += character;
}
function cos(form) {
form.result.value = Math.cos(form.display.value);
}
function sin(form) {
form.result.value = Math.sin(form.display.value);
}
function tan(form) {
form.result.value = Math.tan(form.display.value);
}
function sqrt(form) {
form.result.value = Math.sqrt(form.display.value);
}
function ln(form) {
form.result.value = Math.log(form.display.value);
}
function exp(form) {
form.result.value = Math.exp(form.display.value);
}
function deleteChar(input) {
input.value = input.value.substring(0, input.value.length - 1)
}
function changeSign(input) {
if(input.value.substring(0, 1) == "-")
input.value = input.value.substring(1, input.value.length)
else
input.value = "-" + input.value
}
function compute(form) {
form.result.value = eval(form.display.value)
}
function square(form) {
form.result.value = eval(form.display.value) * eval(form.display.value)
}
function checkNum(str) {
for (var i = 0; i < str.length; i++) {
var ch = str.substring(i, i+1)
if (ch < "0" || ch > "9") {
if (ch != "/" && ch != "*" && ch != "+" && ch != "-" && ch != "."
&& ch != "(" && ch!= ")") {
alert("invalid entry!")
return false
}
}
}
return true
}
</script>
</body>
</html>
Вешаю на elem.onclick = function compute(form) {
form.result.value = eval(form.display.value)
}
не срабатывает