function validateInput(regexString) {
    var theEvent = window.event || event;
    var key = theEvent.keyCode || theEvent.which;
    if (key >= 46) {
        key = String.fromCharCode(key);
        var regex = new RegExp("^" + regexString + "$");
        if (!regex.test(key)) {
            theEvent.returnValue = false;
            if (theEvent.preventDefault) {
                theEvent.preventDefault();
            }
        }
    }
}

function validateNotHebrew(event){
	validateInput('[a-z]');
}

function validateHebrew(event){
	validateInput('[\u0590-\u05FF]');
}

function validateOnlyHebrewAndEnglish(event) {
	validateInput('[\u0590-\u05FFa-zA-Z]');
}

function validateDigits(event){
	validateInput('[0-9]');
}