function setFocus(){
	if(this.value == "Post Code" || this.value == "Professional Name") this.value = ""; // Only if user hasn't entered anything
	this.style.color = "#222;"
}

function setBlur(){
	var fieldValue;
	if(this.value == ""){ // Only reset field value & colour if its empty
		switch(this.id){
			case "postcode":
				fieldValue = "Post Code";
				break;
			case "business_name":
				fieldValue = "Professional Name";
				break;
		}
		this.value = fieldValue;
		this.style.color = "#BBB;"
	}
}

window.onload = function(){
	var postCode 		 = document.getElementById("postcode");
	var professional = document.getElementById("business_name");
	
	postCode.onfocus 		 = setFocus;
	professional.onfocus = setFocus;
	
	postCode.onblur			= setBlur;
	professional.onblur	= setBlur;
}