แบบนี้ต้องทำไงครับ [head]Code (js)[/head][js]<script language="javascript">

<script language="javascript">
									
									function doUnback(value){
   var Old = value.substring(0,--value.length);
   var keyvalue = value.substring(--value.length,value.length);
   if ((keyvalue==1)||(keyvalue==2)||(keyvalue==3)||(keyvalue==4)|| (keyvalue==5)||(keyvalue==6)||(keyvalue==7)|| (keyvalue==8)||(keyvalue==9)||(keyvalue==0)){
      
      alert(" ห้ามป้อนเลข");
	  document.form1.staff_name.value=Old;
	    return false; 
   }
   
   

}
</script>
<form name="form1" action="" method ="POST" enctype="multipart/form-data">
<input name="staff_name" type="text" id="staff_name" onkeyup="doUnback(value)"/>
<input name="staff_sname" type="text" id="staff_sname" onkeyup="doUnback(value)"/>
  <input type="submit" name="action" value="Submit" onClick="return checkForm();"/>
</form>