function SadeceRakam(e,allowedchars){
	var key=e.charCode==undefined?e.keyCode:e.charCode;
	if((/^[0-9]+$/.test(String.fromCharCode(key)))||key==0||key==13||isPassKey(key,allowedchars)){
		return true;
		}else{
		return false;
		}
}
function isPassKey(key,allowedchars){if(allowedchars!=null){for(var i=0;i<allowedchars.length;i++){if(allowedchars[i]==String.fromCharCode(key))return true;}}return false;}
function SadeceRakamBlur(e,clear){var nesne=e.target?e.target:e.srcElement;var val=nesne.value;val=val.replace(/^\s+|\s+$/g,"");if(clear)val=val.replace(/\s{2,}/g," ");nesne.value=val;}



<!-- input icin -->
<!-- <input type="text" id="txtInput" onkeypress="return SadeceRakam(event);" onblur="SadeceRakamBlur(event,false);" />-->

<!-- textarea icin -->
<!-- <textarea cols="50" rows="10" id="txtArea" onkeypress="return SadeceRakam(event,['-']);" onblur="SadeceRakamBlur(event,true);"> </textarea>-->