ไม่ทราบว่าเราสามารถนำค่า ตัวเลขใน String มาเปรียบเทียบค่ากับ ตัวเลข int ปกติได้ไหมครับ

         <form action="" method="post" name="position">
        <table width="100%" border="0" align="center" cellpadding="5" cellspacing="0">
          <tr>
            <td align="center">
<input type="text" name="num4" onkeyup="next_num5();" maxlength="1" value="<?php echo @$_REQUEST['num4'];?>" style="width:35px; height:35px;text-align:center; font-size:24px;"/>
<input type="text" name="num5" onkeyup="next_num6();" maxlength="1" value="<?php echo @$_REQUEST['num5'];?>" style="width:35px; height:35px;text-align:center; font-size:24px;"/>
<input type="text" name="num6" onkeyup="next_num7();" maxlength="1" value="<?php echo @$_REQUEST['num6'];?>" style="width:35px; height:35px;text-align:center; font-size:24px;"/>
<input type="text" name="num7" onkeyup="next_num8();" maxlength="1" value="<?php echo @$_REQUEST['num7'];?>" style="width:35px; height:35px;text-align:center; font-size:24px;"/>
<input type="text" name="num8" onkeyup="next_num9();" maxlength="1" value="<?php echo @$_REQUEST['num8'];?>" style="width:35px; height:35px;text-align:center; font-size:24px;"/>
<input type="text" name="num9" onkeyup="next_num10();" maxlength="1" value="<?php echo @$_REQUEST['num9'];?>" style="width:35px; height:35px;text-align:center; font-size:24px;"/>
<input type="text" name="num10" maxlength="1" value="<?php echo @$_REQUEST['num10'];?>" style="width:35px; height:35px;text-align:center; font-size:24px;"/>            
<br /><br />            
<input type="submit" value="Count"/>
            </td>
          </tr>
        </table>
        </form>
<?php
		if($_POST){
		$check_blank = "";

		if($_POST['num4']!=''){
			$check_blank[] = ' $numcount != 4 ';
			}    
		if($_POST['num5']!=''){
			$check_blank[] = ' $numcount != 5 ';
			}   
		if($_POST['num6']!=''){
			$check_blank[] = ' $numcount != 6 ';
			}    
		if($_POST['num7']!=''){
			$check_blank[] = ' $numcount != 7 ';
			}    
		if($_POST['num8']!=''){
			$check_blank[] = ' $numcount != 8 ';
			}    
		if($_POST['num9']!=''){
			$check_blank[] = ' $numcount != 9 ';
			}    
		if($_POST['num10']!=''){
			$check_blank[] = ' $numcount != 10 ';
			}
		
		$blank_imp = implode(" && ", $check_blank);
		
			
		echo $blank_imp."<br /><br /><br />";
		
		for($numcount = 4; $numcount <= 10; $numcount++ ){
			if( $blank_imp ){
				echo $numcount."<br />";
			}
		}
       }
?>