<SCRIPT LANGUAGE="JavaScript"> function addChar(input, character) { if(input.value == null || input.value == "0") input.value = character else input.value += character } function cos(form) { form.display.value = Math.cos(form.display.value); } function sin(form) { form.display.value = Math.sin(form.display.value); } function tan(form) { form.display.value = Math.tan(form.display.value); } function sqrt(form) { form.display.value = Math.sqrt(form.display.value); } function ln(form) { form.display.value = Math.log(form.display.value); } function exp(form) { form.display.value = Math.exp(form.display.value); } function deleteChar(input) { input.value = input.value.substring(0, input.value.length - 1) } function changeSign(input) { if(input.value.substring(0, 1) == "-") input.value = input.value.substring(1, input.value.length) else input.value = "-" + input.value } function compute(form) { form.display.value = eval(form.display.value) } function square(form) { form.display.value = eval(form.display.value) * eval(form.display.value) } function checkNum(str) { for (var i = 0; i < str.length; i++) { var ch = str.substring(i, i+1) if (ch < "0" || ch > "9") { if (ch != "/" && ch != "*" && ch != "+" && ch != "-" && ch != "." && ch != "(" && ch!= ")") { alert("invalid entry!") return false } } } return true } </SCRIPT>

<FORM NAME="sci-calc"> <TABLE CELLSPACING="0" CELLPADDING="1"> <TR> <TD COLSPAN="5" ALIGN="center"><INPUT NAME="display" VALUE="0" SIZE="28" MAXLENGTH="25"></TD> </TR> <TR> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" exp " ONCLICK="if (checkNum(this.form.display.value)) { exp(this.form) }"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" 7 " ONCLICK="addChar(this.form.display, '7')"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" 8 " ONCLICK="addChar(this.form.display, '8')"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" 9 " ONCLICK="addChar(this.form.display, '9')"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" / " ONCLICK="addChar(this.form.display, '/')"></TD> </TR> <TR> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" ln " ONCLICK="if (checkNum(this.form.display.value)) { ln(this.form) }"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" 4 " ONCLICK="addChar(this.form.display, '4')"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" 5 " ONCLICK="addChar(this.form.display, '5')"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" 6 " ONCLICK="addChar(this.form.display, '6')"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" * " ONCLICK="addChar(this.form.display, '*')"></TD> </TR> <TR> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" sqrt " ONCLICK="if (checkNum(this.form.display.value)) { sqrt(this.form) }"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" 1 " ONCLICK="addChar(this.form.display, '1')"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" 2 " ONCLICK="addChar(this.form.display, '2')"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" 3 " ONCLICK="addChar(this.form.display, '3')"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" - " ONCLICK="addChar(this.form.display, '-')"></TD> </TR> <TR> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" sq " ONCLICK="if (checkNum(this.form.display.value)) { square(this.form) }"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" 0 " ONCLICK="addChar(this.form.display, '0')"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" . " ONCLICK="addChar(this.form.display, '.')"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" +/- " ONCLICK="changeSign(this.form.display)"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" + " ONCLICK="addChar(this.form.display, '+')"></TD> </TR> <TR> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" ( " ONCLICK="addChar(this.form.display, '(')"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE="cos" ONCLICK="if (checkNum(this.form.display.value)) { cos(this.form) }"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" sin" ONCLICK="if (checkNum(this.form.display.value)) { sin(this.form) }"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" tan" ONCLICK="if (checkNum(this.form.display.value)) { tan(this.form) }"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE=" ) " ONCLICK="addChar(this.form.display, ')')"></TD> </TR> <TR> <TD ALIGN="center"><INPUT TYPE="button" VALUE="clear" ONCLICK="this.form.display.value = 0 "></TD> <TD ALIGN="center" COLSPAN="3"><INPUT TYPE="button" VALUE="backspace" ONCLICK="deleteChar(this.form.display)"></TD> <TD ALIGN="center"><INPUT TYPE="button" VALUE="enter" NAME="enter" ONCLICK="if (checkNum(this.form.display.value)) { compute(this.form) }"></TD> </TR> </TABLE> </FORM> <p align="center"><font face="arial" size="-2">This free script provided by</font><br> <font face="arial, helvetica" size="-2"><a href="http://javascriptkit.com">JavaScript Kit</a></font></p>