function isValidSignUp(form){
	var filter  = /^[a-zA-Z0-9-_]+(\.[a-zA-Z0-9-_]+)*@([a-zA-Z_0-9-]+\.)+[a-zA-Z]{2,7}$/;

	if(form.username.value.trim() == ''){
		alert('Email address is empty !');
		return false;
	}
	else if(!filter.test(form.username.value.trim())){
		alert('Your Email address seems to be incorrect. Please check again !');
		return false;
	}
	else if(form.password.value.trim() == ''){
		alert('Password field is empty !');
		return false;
	}
	else if(form.password.value.trim().length < 6){
		alert('Password length must be at least 6 characters !');
		return false;
	}
	else if(form.password.value.trim() != form.confirm_password.value.trim()){
		alert('Incorrect confirm password !');
		return false;
	}
	else if(form.random_image_value.value.trim() == ''){
		alert('Spam protection value field is empty !');
		return false;
	}
	else if(form.address_line_1.value.trim() != '' || form.address_line_2.value.trim() != '' || form.city.value.trim() != ''){
		if(form.district.value == '- Select -'){
			alert('You have not selected the district !');
			return false;
		}	
	}
	
	return true;
}

String.prototype.trim = function() {
	return this.replace(/^\s+|\s+$/g,"");
}