wangtian Posted April 6, 2011 Share Posted April 6, 2011 hi, I want to calculate selectbox value in a form. for example: item price * Quantity. it's works fine if it only have one calculation in the form. function calculate(){document.calcform.total.value =(document.calcform.Chassis.value)*(document.calcform.Quantity.value) } howerver, when when I have more than one calculation, it gives me "NaN.00" here is the function calculate(){ document.calcform.total.value = (document.calcform.Motherboard.value)*(document.calcform.Quantity.value)+(document.calcform.Chassis.value)*(document.calcform.Quantity1.value) } I also posted a picture about the result. Anyone can help me to fix it? I appreciate it. here is all my code on the page: <html> <head> <title> </title> <style type = "text/css"> .SelectClass { font-size: 15px; } table { font-size: .9em; border: 3px groove; padding: 0px; background-color: #dddddd; } .mycss { font-weight:normal;font-style:italic;color:#000000;letter-spacing:1pt;word-spacing:2pt;font-size:36px;text-align:left;font-family:courier new, courier, monospace;line-height:1; } </style> <script LANGUAGE="JavaScript"> function dp(price) { string = "" + price; number = string.length - string.indexOf('.'); if (string.indexOf('.') == -1) return string + '.00'; if (number == 1) return string + '00'; if (number == 2) return string + '0'; if (number > 3) return string.substring(0,string.length-number+3); return string; } function calculate(){ document.calcform.total.value = dp((document.calcform.Motherboard.value)*(document.calcform.Quantity.value)+(document.calcform.Chassis.value)*(document.calcform.Quantity1.value)) } </script> </head> <body onload="calculate"> <div class="mycss"><center>Order List</center></div><br /> <center> <form name="calcform" method="post" action="test2.php"> <table border="0" width="800"> <tr> <td align="right" colspan="2"> <font size="6">$</font><input name="total" style="border:0px solid #000000; background-color:#E6FBF4; font-size: 25.5px;" type="text" value="0.00" ONCHANGE="calculate()"/> </td></tr> <tr> <td><font size="+1"> Product Name</font> </td> <td><font size="+1">Quantity</font></td></tr> <td colspan="2"> <?php mysql_connect("host", "user", "pass") or die(mysql_error()); mysql_select_db("a4202648_wang") or die(mysql_error()); echo "<table width='100%'>"; echo "<tr><td align='left' width='90%'>"; $result = mysql_query("SELECT Motherboard_Part_Number, Motherboard_Name, Motherboard_Price FROM Motherboard where Motherboard_Part_Number='MB-435ED-3'") or die(mysql_error()); echo '<select id="Motherboard" class="SelectClass" name="Motherboard" ONCHANGE="calculate()">'; // keeps getting the next row until there are no more to get while($row = mysql_fetch_array( $result )) { // Print out the contents of each row into a table echo '<option Name="Motherboard" value= ',$row['Motherboard_Price'],'>',$row['Motherboard_Part_Number'],' ',$row['Motherboard_Name'],' $',$row['Motherboard_Price'],' ','</option>'; } echo '</select>'; echo "</td>"; echo "<td align='right' width='10%'>"; $result= mysql_query("SELECT Number FROM Quantity") or die(mysql_error()); echo '<select id="Quantity" class="SelectClass" name="Quantity" Value="Quantity" ONCHANGE="calculate()" >'; // keeps getting the next row until there are no more to get while($row = mysql_fetch_array( $result)) { // Print out the contents of each row into a table echo '<option value=',$row['Number'],'>',$row['Number'],'</option>'; } echo '</select>'; echo "</td></tr>"; echo "<tr><td align='left' width='90%'>"; $result = mysql_query("SELECT Chassis_Part_Number, Chassis_Name, Chassis_Price FROM Chassis where Chassis_Form_Factor='ATX'") or die(mysql_error()); echo '<select id="Chassis" class="SelectClass" name="Chassis" ONCHANGE="calculate()">'; // keeps getting the next row until there are no more to get while($row = mysql_fetch_array( $result )) { // Print out the contents of each row into a table echo '<option Name="Chassis" value= ',$row['Chassis_Price'],'>',$row['Chassis_Part_Number'],' ',$row['Chassis_Name'],' $',$row['Chassis_Price'],' ','</option>'; } echo '</select>'; echo "</td>"; echo "<td align='right' width='10%'>"; $result= mysql_query("SELECT Number FROM Quantity") or die(mysql_error()); echo '<select id="Quantity" class="SelectClass" name="Quantity1" Value="Quantity" ONCHANGE="calculate()" >'; // keeps getting the next row until there are no more to get while($row = mysql_fetch_array( $result)) { // Print out the contents of each row into a table echo '<option value=',$row['Number'],'>',$row['Number'],'</option>'; } echo '</select>'; echo "</td></tr>"; echo "</table>"; ?> </td> </tr> <tr><td colspan="2"><input type="submit" /></td></tr> </table> </form> </center> </body> </html> [attachment deleted by admin] Quote Link to comment https://forums.phpfreaks.com/topic/232821-problem-on-the-select-box-calcualtion/ Share on other sites More sharing options...
Pikachu2000 Posted April 6, 2011 Share Posted April 6, 2011 When posting code, please post it within . . . BBCode tags. Quote Link to comment https://forums.phpfreaks.com/topic/232821-problem-on-the-select-box-calcualtion/#findComment-1197569 Share on other sites More sharing options...
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