function  checkForm(this_form){
   
    if  (!hasValue(this_form.email, "TEXT" )) {
                if  (!putMessage("Please enter your email address")){
                        return false; 
                }
        } else {
                if (!checkEmail(this_form.email)){
                        if  (!putMessage("Please enter valid email address")){
                                return false; 
                        }
                }
        }
   
	
        
        return true;    
}



function putMessage(error_message){
        alert(error_message);
        return false;   
}

function checkEmail(email){
        var email_string = email.value; 
        var at_position = email_string.indexOf('@'); 
        var dot_position = email_string.indexOf('.', at_position); 
        var extension = email_string.substring(dot_position+1,email_string.length); 
        
        if(at_position<0){
                return false; 
        } else if (dot_position<0){
                return false; 
        } else if (extension.length<=0){
                return false; 
        } 
        return true; 
}

function hasValue(obj, obj_type){
    if (obj_type == "TEXT" || obj_type == "PASSWORD"){
        if (obj.value.length == 0) 
                return false;
        else 
                return true;
    } else if (obj_type == "SINGLE_VALUE_RADIO" || obj_type == "SINGLE_VALUE_CHECKBOX") {
                if (obj.checked)
                        return true;
                else
                return false;   
        } else if (obj_type == "RADIO" || obj_type == "CHECKBOX") {
                for (i=0; i < obj.length; i++){
                        if (obj[i].checked)
                                return true;
                }
                return false;   
        } else  if (obj_type == "SELECT") {
                if (obj.selectedIndex == 0)
                        return false;
                else
                        return true;
        }
}

function hasValue2(obj1, obj2, obj3, obj4, obj5, obj6){
        var flag = 0;
        for (i=1; i < 7; i++){
                if (obj[i].checked)
                        flag = i;
                }
        if (flag == 0)
                return false;
        else
                return true;
}

function makeRequest(url) {
        var http_request = false;

        if (window.XMLHttpRequest) { // Mozilla, Safari, ...
            http_request = new XMLHttpRequest();
            if (http_request.overrideMimeType) {
                http_request.overrideMimeType('text/xml');
                // See note below about this line
            }
        } else if (window.ActiveXObject) { // IE
            try {
                http_request = new ActiveXObject("Msxml2.XMLHTTP");
            } catch (e) {
                try {
                    http_request = new ActiveXObject("Microsoft.XMLHTTP");
                } catch (e) {}
            }
        }

        if (!http_request) {
            alert('Giving up :( Cannot create an XMLHTTP instance');
            return false;
        }
        http_request.onreadystatechange = function() { alertContents(http_request); };
        http_request.open('GET', url, true);
        http_request.send(null);

    }
	
 function hideLayer(whichLayer) {

if (document.getElementById) {
// this is the way the standards work
document.getElementById(whichLayer).style.visibility = "hidden";
}
else if (document.all) {
// this is the way old msie versions work
document.all[whichlayer].style.visibility = "hidden";
}
else if (document.layers) {
// this is the way nn4 works
document.layers[whichLayer].visibility = "hidden";
}

}

function showLayer(whichLayer) {

if (document.getElementById) {
// this is the way the standards work
document.getElementById(whichLayer).style.visibility = "visible";
}
else if (document.all) {
// this is the way old msie versions work
document.all[whichlayer].style.visibility = "visible";
}
else if (document.layers) {
// this is the way nn4 works
document.layers[whichLayer].visibility = "visible";
}

}

function handleClick(whichClick,theLayer) {

if (whichClick == "hide it") {
// then the user wants to hide the layer
hideLayer(theLayer);

}
else if (whichClick == "show it") {
// then the user wants to show the layer
showLayer(theLayer);
}

}