help with a function please

[supacook2k]

i've got a problem validating my text field. when my calculation is in the display and i click equals if the last character is not a number then it alerts the user the calculation must end with a digit but it also alerts when the calculation in the display is e.g. 9+9 which is correct yet alerts saying calculation must end in a digit and then performs the calculation after clicking ok, basically i just want it to alert when the last character is not a number.

any help greatly appreciated

here's the code i've got for it. (when calling the functions i've got onClick="validateIt();equals();"

function equals() {

document.calculator.display.value=eval(document.calculator.display.value);

}

function validateIt() {

var input=document.calculator.display.value;
var length=input.length-1;

if(isNaN(input.charAt(length))); 

alert("your calculation must end in a digit")

}

[Logic Ali]

i've got a problem validating my text field. when my calculation is in the display and i click equals if the last character is not a number then it alerts the user the calculation must end with a digit but it also alerts when the calculation in the display is e.g. 9+9 which is correct yet alerts saying calculation must end in a digit and then performs the calculation after clicking ok, basically i just want it to alert when the last character is not a number.

any help greatly appreciated

here's the code i've got for it. (when calling the functions i've got onClick="validateIt();equals();"

function equals() {

document.calculator.display.value=eval(document.calculator.display.value);

}

function validateIt() {

var input=document.calculator.display.value;
var length=input.length-1;

if(isNaN(input.charAt(length))); 

alert("your calculation must end in a digit")

}

Your if statement does nothing, therefore the alert is not associated with it and will always execute.